Optical film and optical system including the same for reducing chromatic aberration

Abstract

An optical film includes a plurality of optical repeat units including at least three first ORUs having a thickness within P1% of a same first thickness, wherein each first ORU is separated from each other first ORU by at least one ORU having a thickness more than P1% different from the first thickness, and wherein P1% is in a range from about 1% to about 10%. For incident light incident on the optical film at a first angle of incidence and for at least one polarization state, over a predetermined range of wavelengths, a depth of reflection from a same first major side of the optical film varies non-monotonically with increasing wavelength of the incident light. An optical system includes the optical film for reducing chromatic aberration by at least partially compensating for dispersion of at least one optical component of the optical system.

Description

Technical Field

[0001] This specification relates in its entirety to optical films, such as polymer multilayer optical films, and to optical systems that utilize such optical films. Background Technology

[0002] Optical films may comprise multiple polymer layers arranged as optical repeating units. Optical films can be reflective polarizers and can be used in optical systems such as display systems. Summary of the Invention

[0003] In some aspects, this specification provides an optical film such that, for incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range and / or within a visible wavelength range extending from about 420 nm to about 680 nm, the reflection depth of the optical film from the same first principal side surface of the optical film varies rather than monotonically with increasing wavelength of the incident light. The optical film may include multiple polymer layers, which may be or include multiple alternating first and second layers of polymer, and / or may be arranged as multiple optical repeating units. An optical system may include an optical film for reducing chromatic aberration by at least partially compensating for the dispersion of at least one optical component of the optical system.

[0004] In some aspects, this specification provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, with a total number of at least 10, wherein each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers. The plurality of ORUs includes at least three first ORUs, wherein each first ORU has a thickness within P1% of the same first thickness, and each first ORU is separated from each other first ORU by at least one ORU having a thickness greater than P1% of the first thickness, wherein P1% is in the range of about 1% to about 10%. For incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range, the reflection depth of the optical film from the same first principal side of the optical film varies non-monotonically with increasing wavelength of the incident light.

[0005] In some aspects, this specification provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together and totaling at least 10, wherein each ORU comprises at least a polymer A layer and a different polymer B layer, such that for incident light incident on the optical film at a first incident angle and for at least one polarization state: each ORU has a peak reflectivity at a corresponding resonant wavelength (RW) in the range of about 300 nm to about 3000 nm; for a first wavelength in the visible wavelength range extending from about 420 nm to about 680 nm, the optical film comprises at least three first ORUs, each first ORU having an RW within P1% of the first wavelength, each first ORU being separated from each other first ORU by at least one ORU having an RW greater than P1% of the first wavelength, P1% being in the range of about 1% to about 10%; and in the visible wavelength range, the reflection depth of the optical film from the same first principal side of the optical film varies rather than monotonically with increasing wavelength of the incident light.

[0006] In some aspects, the present invention provides an optical film comprising a macro layer and a plurality of optical repeating units (ORUs) totaling at least 10, the plurality of ORUs being disposed on the same first main surface of the macro layer. The macro layer and the plurality of optical repeating units may be co-extruded and co-stretched with each other. The macro layer may have an average thickness greater than about 500 nm. Each ORU may have an average thickness less than about 1500 nm and includes at least a polymer A layer and different polymer B layers. For incident light incident on the optical film at a first incident angle and for at least a first polarization state, the plurality of ORUs have a first average reflection depth, a second average reflection depth, and a third average reflection depth relative to the first main surface of the macroscopic layer in corresponding non-overlapping first, second, and third wavelength ranges, wherein the second wavelength range is disposed between the first and third wavelength ranges; the second average reflection depth differs from each of the first and third average reflection depths by at least about 1.2 times the difference between the first and third average reflection depths; and each of the first, second, and third wavelength ranges is at least about 20 nm wide and is disposed between about 380 nm and about 2000 nm. For incident light incident on the optical film at the first incident angle and for at least a first polarization state, the optical film has an average reflectivity of at least about 60% in each of the first, second, and third wavelength ranges.

[0007] In some aspects, this specification provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, with a total number of at least 10, wherein each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers, and wherein each ORU has a peak reflectance at a corresponding resonant wavelength (RW), such that when adjacent data points are connected by straight line segments in a scatter plot of the RW of the ORUs against the depth of the ORUs relative to the same principal side of the optical film to form a continuous line plot, the continuous line plot comprises a plurality of first lines that alternate with and intersect with a plurality of second lines, wherein the RW of the ORUs in all the first lines substantially increases with the same condition of increasing or decreasing ORU depth, and the RW of the ORUs in all the second lines substantially decreases with the same condition of increasing or decreasing ORU depth. The intersections form a plurality of alternating peaks and valleys. The first of the multiple first lines comprises multiple first straight line segments extending from the first valley of the multiple alternating peaks and valleys to the first peak of the multiple alternating peaks and valleys. The slope of each first straight line segment has a minimum slope amplitude and a maximum slope amplitude. The minimum slope amplitude may be at least about 5 nm / micrometer. The maximum slope amplitude is at least about 3 times the minimum slope amplitude.

[0008] In some aspects, this specification provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, with a total number of at least 10, wherein each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers, and wherein the ORUs are sequentially numbered from the same first principal side of the optical film to the opposite second principal side of the optical film, such that when adjacent data points in a scatter plot of ORU thickness versus numbering are connected by straight line segments to form a continuous line graph, the continuous line graph comprises a plurality of first lines that alternate with and intersect with a plurality of second lines, wherein the ORU thickness in all first lines substantially increases with the same condition of increasing and decreasing ORU numbering, and wherein the ORU thickness in all second lines substantially decreases with the same condition of increasing and decreasing ORU numbering. The intersections form a plurality of alternating peaks and valleys. The first of the multiple first lines comprises multiple first straight line segments extending from the first valley of the multiple alternating peaks and valleys to the first peak of the multiple alternating peaks and valleys. The slope of each first straight line segment has a minimum slope amplitude and a maximum slope amplitude. The minimum slope amplitude may be at least approximately 0.5 nm per ORU number. The maximum slope amplitude is at least approximately 3 times the minimum slope amplitude.

[0009] In some aspects, this specification provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, with a total number of at least 10, wherein each ORU has a peak reflectivity at a corresponding resonant wavelength (RW) and comprises at least a polymer A layer and different polymer B layers, such that when adjacent data points are connected by straight line segments to form a continuous line graph in a scatter plot of the RW of the ORUs against the depth of the ORUs relative to the same principal side of the optical film, the continuous line graph comprises a plurality of first lines that alternate with and intersect with a plurality of second lines, wherein the RW of the ORUs in all the first lines substantially increases with the same condition of increasing or decreasing ORU depth, and the RW of the ORUs in all the second lines substantially decreases with the same condition of increasing or decreasing ORU depth. The intersections form at least a plurality of alternating peaks and valleys. For each pair of adjacent peaks and valleys in the first plurality of alternating peaks and valleys, the difference in the ORU RW of the peaks and valleys can be greater than about 5 nm and less than about 200 nm.

[0010] In some aspects, this specification provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, with a total number of at least 10, wherein each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers, and wherein the ORUs are sequentially numbered from the same first principal side of the optical film to the opposite second principal side of the optical film, such that when adjacent data points in a scatter plot of the thickness versus number of the ORUs are connected by straight line segments to form a continuous line graph, the continuous line graph comprises a plurality of first lines that alternate with and intersect a plurality of second lines, wherein the ORU thickness in all the first lines substantially increases with the same condition of increasing and decreasing ORU number, and the ORU thickness in all the second lines substantially decreases with the same condition of increasing and decreasing ORU number. The intersections form at least a plurality of alternating peaks and valleys. For each pair of adjacent peaks and valleys in the first plurality of alternating peaks and valleys, the difference in ORU thickness between the peaks and valleys can be greater than about 3 nm and less than about 120 nm.

[0011] In some aspects, the present invention provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, and totaling at least 10. Each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers. The ORUs in the plurality of ORUs may be sequentially numbered from the same first principal side of the optical film to the opposite second principal side of the optical film, such that for a non-overlapping first thickness range and a second thickness range of at least about 5 nm wide, a scatter plot of the thickness of the ORUs versus the numbering includes at least three non-overlapping first groups of sequentially numbered ORUs in the plurality of ORUs, wherein each ORU in each first group has a thickness within a first thickness range; and a second group of at least eight ORUs in the plurality of ORUs, wherein each ORU in the second group has a thickness within a second thickness range. Each first group includes at least three ORUs in the plurality of ORUs that are sequentially numbered. Each first group is separated from each other first group by at least two sequentially numbered ORUs in the plurality of ORUs whose thickness is not within the first thickness range. For incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range, the reflection depth of the optical film from the same first principal side of the optical film changes monotonically with increasing wavelength of the incident light.

[0012] In some aspects, the present invention provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, and totaling at least 10. Each ORU has a peak reflectivity at a corresponding resonant wavelength (RW) and comprises at least a polymer A layer and different polymer B layers. The ORUs in the plurality of ORUs may be sequentially numbered from the same first principal side of the optical film to the opposite second principal side of the optical film, such that for a non-overlapping first wavelength range and a second wavelength range of at least about 15 nm wide, a scatter plot of the RW pairs of the ORUs includes at least three non-overlapping first groups of sequentially numbered ORUs in the plurality of ORUs, wherein each ORU in each first group has an RW in the first wavelength range; and a second group of at least eight ORUs in the plurality of ORUs, wherein each ORU in the second group has an RW in the second wavelength range. Each first group in the first group includes at least three ORUs in the sequentially numbered ORUs in the plurality of ORUs. Each first group is separated from each other first group by at least two sequentially numbered ORUs whose RWs are not within the first wavelength range. For incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range, the reflection depth of the optical film from the same first principal side of the optical film varies rather than monotonically with increasing wavelength of the incident light.

[0013] In some aspects, the present invention provides an optical film comprising a macro layer and a plurality of optical repeating units (ORUs) totaling at least 10, the plurality of ORUs being disposed on the same first master surface of the macro layer. The macro layer and the plurality of optical repeating units may be co-extruded and co-stretched with each other. The macro layer may have an average thickness greater than about 500 nm, and each layer of each ORU may have an average thickness less than about 500 nm. Each ORU comprises at least a polymer A layer and different polymer B layers. When adjacent data points in a scatter plot of ORU thickness versus number are connected by straight line segments to form a continuous line plot, the continuous line plot includes multiple first lines that alternate and intersect with multiple second lines. In the multiple first lines, the ORU thickness in all first lines substantially increases as the ORU number increases or decreases, and in the multiple second lines, the ORU thickness in all second lines substantially decreases as the ORU number increases or decreases, such that for incident light incident on the optical film at a first incident angle and for at least one polarization state: for a first wavelength in the visible wavelength range extending from about 420 nm to about 680 nm, the reflection depth of the multiple ORUs relative to the first master surface of the macroscopic layer is less than about 10 micrometers; and for a wavelength range at least 20 nm wide and substantially centered on the first wavelength, the multiple ORUs have an average reflectivity greater than about 60%.

[0014] In some aspects, the present invention provides an optical film comprising a macro layer and a plurality of optical repeating units (ORUs) totaling at least 10, the plurality of ORUs being disposed on the same first main surface of the macro layer. The macro layer and the plurality of optical repeating units may be co-extruded and co-stretched with each other. The macro layer may have an average thickness greater than about 500 nm, and each layer of each ORU may have an average thickness less than about 500 nm. Each ORU has a peak reflectivity at a corresponding resonant wavelength (RW) and includes at least a polymer A layer and different polymer B layers. When adjacent data points are connected by straight line segments to form a continuous line graph in a scatter plot of the RW of an ORU relative to the depth of the ORU relative to the first master surface of the macroscopic layer, the continuous line graph includes multiple first lines that alternate and intersect with multiple second lines. In the multiple first lines, the ORU RW in all first lines increases substantially with the same condition of increasing or decreasing ORU depth, and in the multiple second lines, the ORU RW in all second lines decreases substantially with the same condition of increasing or decreasing ORU depth, such that for incident light incident on the optical film at a first incident angle and for at least one polarization state: for a first wavelength in the visible wavelength range extending from about 420 nm to about 680 nm, the reflection depth of the multiple ORUs relative to the first master surface of the macroscopic layer is less than about 10 micrometers; and for a wavelength range at least 20 nm wide and substantially centered on the first wavelength, the multiple ORUs have an average reflectivity greater than about 60%.

[0015] In some aspects, the present invention provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, and totaling at least 10. Each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers. The ORUs in the plurality of ORUs may be sequentially numbered from the same first principal side of the optical film to the opposite second principal side of the optical film. A scatter plot of the thickness of the ORUs versus the numbering includes at least three non-overlapping first groups of ORUs. Each group in the first group includes at least three ORUs in the sequentially numbered plurality of ORUs, including a first ORU and a second ORU having a corresponding maximum and minimum thickness among the at least three ORUs in the group, wherein the minimum thickness and the maximum thickness in the group differ from each other by at least 15%. For each ORU in the first ORU and the second ORU in the at least three non-overlapping first groups of ORUs, the thickness of the ORU may be within about 10% of each other. For incident light incident on the optical film at a first incident angle and for at least one polarization state, in the wavelength range of about 420 nm to about 680 nm, the reflection depth of the optical film from the same first principal side of the optical film changes with increasing wavelength of the incident light rather than monotonically.

[0016] In some aspects, the present invention provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, with a total number of at least 10. Each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers. Each ORU has a peak reflectivity at a corresponding resonant wavelength (RW). A scatter plot of the RW of the ORU versus the depth of the ORU relative to the same principal side of the optical film includes at least three non-overlapping first groups of ORUs. Each group in the first group includes at least three sequentially numbered ORUs from the plurality of ORUs, including a first ORU and a second ORU having a corresponding maximum and minimum RW among the at least three ORUs in the group. The minimum and maximum RWs in the group differ from each other by at least 15%. For each ORU in the first and second ORUs of the at least three non-overlapping first groups of ORUs, the RW of the ORU may be within about 10% of each other. For incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range, the reflection depth of the optical film from the same first principal side of the optical film varies rather than monotonically with increasing wavelength of the incident light.

[0017] In some aspects, the present invention provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, and in total number at least 10. Each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and a different polymer B layer. The ORUs in the plurality of ORUs may be sequentially numbered from the same first principal side of the optical film to the opposite second principal side of the optical film, such that a scatter plot of the average thickness of the sequentially numbered ORUs in the plurality of ORUs includes at least three non-overlapping groups of ORUs, wherein each group includes at least two ORUs in the sequentially numbered ORUs in the plurality of ORUs. For each pair of adjacent first and second groups in the at least three groups, the first group includes the first ORU closest to the second group, and the second group includes the second ORU closest to the first group, wherein the average thickness of the first ORU and the second ORU differs from that of the second ORU by at least about 5%. For incident light incident on the optical film at a first incident angle and for at least one polarization state: for at least a first wavelength in the visible light range extending from about 420 nm to about 680 nm, the plurality of ORUs and at least one group of the at least three non-overlapping groups have corresponding optical reflectivities R and R1; for at least a second wavelength in the visible light range different from the first wavelength, the plurality of ORUs and a group of at least three sequentially numbered ORUs that do not overlap with any of the at least three non-overlapping groups of the ORUs have corresponding optical reflectivities R' and R1'; and in the visible wavelength range, the reflection depth of the optical film from the same first principal side of the optical film varies non-monotonically with increasing wavelength of the incident light, where R > R1 > 10%, R / R1 ≥ 1.1, R1' ≥ 50%, and 1.25 > R' / R1'.

[0018] In some aspects, the present invention provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, and totaling at least 10 ORUs. The ORUs in the plurality of ORUs may be sequentially numbered from the same first principal side of the optical film to the opposite second principal side of the optical film. Each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers. Each ORU has a peak reflectance at a corresponding resonant wavelength (RW) such that a scatter plot of RW versus depth of the ORU relative to the first principal side of the optical film includes at least three non-overlapping groups of ORUs, wherein each group includes at least two sequentially numbered ORUs from the plurality of ORUs. For each pair of adjacent first and second groups in the at least three groups, the first group includes the first ORU closest to the second group, and the second group includes the second ORU closest to the first group, wherein the RW of the first ORU and the second ORU differs by at least about 5%. For incident light incident on the optical film at a first incident angle and for at least one polarization state: for at least a first wavelength in the visible light range extending from about 420 nm to about 680 nm, the plurality of ORUs and at least one group of the at least three non-overlapping groups have corresponding optical reflectivities R and R1; for at least a second wavelength in the visible light range different from the first wavelength, the plurality of ORUs and a group of at least three sequentially numbered ORUs that do not overlap with any of the at least three non-overlapping groups of the ORUs have corresponding optical reflectivities R' and R1'; and in the visible wavelength range, the reflection depth of the optical film from the first principal side of the optical film varies non-monotonically with increasing wavelength of the incident light, wherein R > R1 > 10%, R / R1 ≥ 1.1, R1' ≥ 50%, and 1.25 > R' / R1'.

[0019] In some aspects, the present invention provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, and totaling at least 10 ORUs. Each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers. The ORUs may be sequentially numbered from the same first principal side of the optical film to the opposite second principal side, such that for a first thickness range at least about 20 nm wide, a scatter plot of the ORU thickness versus numbering includes at least a first non-overlapping plot, a second non-overlapping plot, and a third non-overlapping plot of the sequentially numbered ORUs, wherein each ORU in each of the at least first, second, and third non-overlapping plots has a thickness within the first thickness range. Each of the at least first, second, and third non-overlapping plots includes at least two ORUs from the plurality of ORUs. The magnitudes of the slopes of the best linear fits to at least two of the at least first to third non-overlapping plots differ by at least about 20%. For incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range, the reflection depth of the optical film from the first principal side of the optical film changes monotonically with increasing wavelength of the incident light.

[0020] In some aspects, the present invention provides an optical film comprising a plurality of optical repeating units (ORUs) co-extruded and co-stretched together, and totaling at least 10. Each ORU may have an average thickness of less than about 1500 nm and comprises at least a polymer A layer and different polymer B layers. Each ORU has a peak reflectivity at a corresponding resonant wavelength (RW), such that for a first wavelength range at least about 40 nm wide, a scatter plot of the RW of the ORU versus the depth of the ORU relative to the same principal side of the optical film includes at least a first non-overlapping plot, a second non-overlapping plot, and a third non-overlapping plot of the ORU, wherein each ORU in each of the at least first, second, and third non-overlapping plots has an RW within the first wavelength range. Each non-overlapping scatter plot in at least the first, second, and third non-overlapping plots includes at least two ORUs of the plurality of ORUs and has a slope as the rate of change of RW relative to depth under the same first RW. The slopes of at least two of the first to third figures differ by at least approximately 20%. For incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range, the reflection depth of the optical film from its first principal side varies rather than monotonically with increasing wavelength of the incident light.

[0021] In some aspects, this specification provides an optical film comprising a plurality of polymer layers stacked along the thickness direction of the optical film, such that when a substantially monochromatic first ray having a first wavelength and optical intensity Ii1 is incident on the plurality of polymer layers at a first incident angle of at least 5 degrees, and a substantially monochromatic second ray having a second wavelength different from the first wavelength and optical intensity Ii2 ≤ Ii1 is incident on the plurality of polymer layers at the first incident angle, the plurality of polymer layers reflects the incident first ray without reflecting the incident second ray into at least two spaced-apart first reflected rays having corresponding at least two first optical intensities, wherein each of the at least two first optical intensities is greater than about 0.1 Ii1, and the plurality of polymer layers reflects the incident second ray into second reflected rays having a second optical intensity greater than about 0.5 Ii2, wherein the second optical intensity is greater than each of the at least two first optical intensities.

[0022] In some aspects, this specification provides an optical system comprising: a display configured to form and emit an image; at least one optical component having dispersion; and an optical film of this specification in optical communication with each of the display and the at least one optical component. The optical film may be configured to at least partially compensate for the dispersion of the at least one optical component.

[0023] In some aspects, this specification provides an optical system comprising a display configured to form and emit an image including overlapping first and second emitted image rays having corresponding first and second wavelengths separated by at least about 20 nm, wherein the optical system can be configured to display a virtual image of the emitted image to an observer; at least one optical component having dispersion; and an optical film comprising a plurality of polymer layers and configured to at least partially compensate for the dispersion of the at least one optical component. Each of the plurality of polymer layers may have an average thickness of less than about 500 nm. For incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range including the first and second wavelengths, the reflection depth of the optical film from the same first principal side of the optical film varies rather than monotonically with increasing wavelength of the incident light. The optical system allows the optical interaction between the at least one optical component and the overlapping first and second emitted image rays to laterally separate the first and second emitted image rays, such that when incident on the optical film, the first and second emitted image rays are separated by a first distance G1. The plurality of polymer layers reflect the incident first and second emitted image rays into corresponding reflected first and second image rays separated by a second distance G2. G2 is at least 10% smaller than G1.

[0024] These and other aspects will become apparent from the detailed description that follows. However, in no way should this brief overview be construed as limiting the subject matter for which protection may be claimed. Attached Figure Description

[0025] Figure 1 This is a schematic cross-sectional view of an optical film according to some implementation schemes.

[0026] Figure 2 It is a schematic diagram of the thickness or RW of at least a portion of the optical repeating unit (ORU) of an optical film according to some embodiments, relative to the ORU numbering or depth from the same main side of the optical film.

[0027] Figure 3 This is a schematic diagram of the ORU thickness or RW relative to the ORU numbering or depth from the same main side of the optical film, according to some implementation schemes.

[0028] Figures 4A to 4B It is a schematic diagram of the ORU thickness or RW of at least a portion of an optical film according to some embodiments, relative to the ORU numbering or depth from the same main side of the optical film.

[0029] Figures 5A to 5BIt is a schematic diagram of the ORU thickness or RW of at least a portion of another optical film according to some embodiments, relative to the ORU numbering or depth from the same main side of the optical film.

[0030] Figure 6 It is a diagram of the resonant wavelength relative to the depth from the same main side of the optical film, based on some implementation schemes.

[0031] Figure 7 It shows Figure 6 The resonant wavelength is used for polynomial fitting of the non-overlapping portion of the depth graph.

[0032] Figure 8 yes Figure 7 The slope of the non-overlapping plot versus the resonant wavelength.

[0033] Figure 9 This is a diagram showing the ORU numbering based on the ORU thickness of some implementation schemes.

[0034] Figure 10 It shows the Figure 9 The ORU thickness is linearly fitted to the non-overlapping portion of the ORU numbered plot.

[0035] Figure 11A It is a diagram of the resonant wavelength relative to the depth from the same main side of another optical film, based on some implementation schemes.

[0036] Figure 11B yes Figure 11A Part of the diagram.

[0037] Figure 12A This is a diagram showing the ORU numbering based on the ORU thickness of the optical film in some implementation schemes.

[0038] Figure 12B yes Figure 12A Part of the diagram.

[0039] Figures 13 to 14 This is a schematic diagram of the reflection depth relative to wavelength from the same main side of the optical film, according to some implementation schemes.

[0040] Figure 15 This is a schematic illustration of reflection from an optical film according to some implementation schemes.

[0041] Figure 16 This is a schematic diagram of the reflectivity of an optical repeating unit relative to wavelength according to some implementation schemes.

[0042] Figures 17 to 18 This is a schematic diagram of the reflectivity of an optical film and the non-overlapping group of the ORU of the optical film versus wavelength according to some implementation schemes.

[0043] Figure 19 It is a schematic cross-sectional view of an optical system according to some implementation schemes. Detailed Implementation

[0044] Reference is made in the following description to the accompanying drawings, which form part of this disclosure and in which various embodiments are illustrated by way of example. The drawings are not necessarily drawn to scale. It should be understood that other embodiments may be conceived and practiced without departing from the scope or spirit of this specification. Therefore, the following detailed description should not be considered limiting.

[0045] As is known in the art, multilayer optical films comprising multiple optical repeating units (e.g., alternating first and second polymer layers) can be used to provide desired reflection and transmission within a desired wavelength range by appropriately selecting layer thicknesses and refractive index differences. Multilayer optical films and methods of manufacturing multilayer optical films are described, for example, in U.S. Patent Nos. 5,882,774 (Jonza et al.); 6,783,349 (Neavin et al.); 6,949,212 (Merrill et al.); 6,967,778 (Wheatley et al.); 9,162,406 (Neavin et al.); and 11,493,677 (Haag et al.). The optical repeating unit of a multilayer optical film is typically the smallest distinguishing unit of an optical layer that repeats along the thickness direction of the optical film. Optical repeating units typically comprise at least two distinct layers (e.g., a first layer with a higher refractive index and a second layer with a lower refractive index) and may optionally include additional layers described, for example, in U.S. Patent Nos. 5,103,337 (Schrenk et al.); 5,360,659 (Arends et al.); 5,540,978 (Schrenk); and 6,207,260 (Wheatley et al.), and, for example, International Patent Application Publication No. WO 2022 / 195373 (Huseby et al.).

[0046] Multilayer optical films can be interference stacks that reflect light by stacking optical repeating units (e.g., a bilayer unit cell comprising two quarter-wavelength layers) together, where there is a refractive index contrast between the layers of the optical repeating units. Each optical repeating unit is characterized by a reflection band having an inherent optical power and bandwidth determined by the refractive index contrast and f-ratio of the optical repeating unit. The f-ratio of the optical repeating unit is the optical thickness of the layers of the optical repeating unit divided by the total optical thickness of the optical repeating unit. In the case of a bilayer optical repeating unit, the f-ratio of the higher refractive index layer of the bilayer is considered the f-ratio of the optical repeating unit. More generally, an optical repeating unit can be characterized by n-1 independent f-ratios, where n is the number of layers of the optical repeating unit. Because the inherent optical power and bandwidth of a single optical repeating unit are often too weak and too narrow for practical applications, many optical repeating units are stacked and graded to increase the overall optical power and bandwidth. Thus, different wavelengths are reflected at different depths within the multilayer optical film depending on which optical repeating units are in a resonant or non-resonant state. In many applications, this reflection depth dispersion does not significantly affect key performance indicators. However, in imaging optics applications, this property can induce lateral shifts in light of different wavelengths, leading to chromatic aberration, pixel blur, resolution loss, and other artifacts. Other optical components, such as lenses, can also induce chromatic aberration, and compensating lenses are typically added to imaging systems to correct for overall chromatic aberration.

[0047] According to some embodiments, it has been found that the ability to tune and design reflection depth dispersion within optical films (such as reflective polarizers in polarizing beam splitters or folding optical lenses) can mitigate and, in some cases, eliminate or substantially eliminate chromatic aberration. For example, according to some embodiments, it has been found that an optical system may include an optical film and at least one optical component having dispersion, wherein the optical film has a reflection depth that varies non-monotonically with wavelength from the same first principal side of the optical film to correct for dispersion. For example, the reflection depth for blue and red wavelengths may be similar, while the reflection depth for green wavelengths may be significantly different from the reflection depths for red and green wavelengths in order to correct for dispersion.

[0048] Figure 1This is a schematic cross-sectional view of an optical film 300 according to some embodiments. The optical film 300 may include a plurality of optical repeating units (ORUs) 10. Each ORU 10 typically includes at least one polymer A layer and different polymer B layers, and may optionally include additional layers. In some embodiments, the ORUs are co-extruded and co-stretched with each other. In some embodiments, all layers of the optical film 300 are co-extruded and co-stretched with each other. In some embodiments, the total number of ORUs 10 is at least 10, 25, 50, 100, 150, 200, 250, 300, 350, 400, 450, or 500. The number of ORUs 10 may be, for example, up to 2000, 1500, 1000, 800, or 700.

[0049] In some implementations, each ORU in ORU 10 has an average thickness less than about 1500 nm, 1250 nm, 1000 nm, 900 nm, 800 nm, 700 nm, 600 nm, 500 nm, 450 nm, 400 nm, 350 nm, or 300 nm. Each ORU 10 may have an average thickness greater than, for example, about 50 nm, 75 nm, 100 nm, 150 nm, or 175 nm. The average thickness of a layer is the average (unweighted mean) of the layer thickness over the total area of ​​the layer. The average thickness of an ORU is the average of the total thickness of the ORU (the sum of the thicknesses of the layers of the ORU). Unless otherwise indicated or unless the context clearly indicates otherwise, the thickness of a layer or ORU may be understood as the average thickness of the layer or ORU. In some embodiments, each layer of each ORU in ORU 10 (e.g., each of layers A and B) has an average thickness less than about 500 nm, 450 nm, 400 nm, 350 nm, 300 nm, 250 nm, or 200 nm. Each layer of each ORU 10 may have an average thickness greater than, for example, about 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, or 50 nm. In some embodiments, optical film 300 includes a plurality of polymer layers (e.g., layers A and B), wherein each of the plurality of polymer layers has an average thickness less than about 500 nm, 450 nm, 400 nm, 350 nm, 300 nm, 250 nm, or 200 nm. Each of the plurality of polymer layers may have an average thickness greater than, for example, about 10 nm, 15 nm, 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, or 50 nm. The optical film 300 may have an average total thickness of at least about 10 micrometers, 15 micrometers, 20 micrometers, 25 micrometers, 30 micrometers, 35 micrometers, 40 micrometers, 45 micrometers, or 50 micrometers. The average total thickness of the optical film 300 may be, for example, up to about 400 micrometers, 300 micrometers, 250 micrometers, 200 micrometers, 175 micrometers, 150 micrometers, 125 micrometers, or 100 micrometers. In some embodiments, the plurality of optical repeating units 10 have an average total thickness within any of these ranges (e.g., corresponding to...). Figure 15 (S4 in the example). For example, the plurality of optical repeating units 10 may have an average total thickness in the range of, for example, about 10 micrometers to about 400 micrometers, or about 15 micrometers to about 300 micrometers, or about 20 micrometers to about 200 micrometers.

[0050] The ORUs can be sequentially numbered from the same first main side 301 of the optical film 300 to the opposite second main side 302 of the optical film 300. In some embodiments, the optical film 300 includes a plurality of polymer layers (e.g., layer A and layer B). The plurality of polymer layers can be stacked along the thickness direction (z-direction) of the optical film 300 and can be sequentially numbered from the same first main side 301 of the optical film 300 to the opposite second main side 302 of the optical film 300.

[0051] The layers of the optical repeating unit 10 may be referred to as microlayers, optical layers, or interference layers. In some embodiments, the optical film 300 includes at least one additional layer 124, 125, 126. For example, in some embodiments, the optical film 300 includes at least one macrolayer 124, 126, wherein each of the at least one macrolayer 124, 126 has an average thickness greater than about 500 nm, 600 nm, 750 nm, 1000 nm, 1500 nm, or 2000 nm. The average thickness of each macrolayer 124, 126 may be, for example, at most about 50 micrometers, 30 micrometers, 20 micrometers, or 10 micrometers. The at least one macrolayer 124, 126 may, for example, comprise the outermost surface layer of the optical film 300 and / or may comprise protective boundary layers between adjacent groups of layers of the optical film 300. Layer 125 may, for example, be a protective boundary layer and / or may be a macrolayer. In some embodiments, layer 125 is omitted. In some embodiments, the plurality of polymer layers and / or the plurality of ORUs 10 are disposed on the at least one macro layer 124, 126. In some embodiments, the optical film 300 includes a macro layer 124 and a plurality of optical repeating units (ORUs) 10 totaling at least 10 (or within the range described elsewhere herein), the plurality of ORUs being disposed on the same first main surface 124a of the macro layer 124. In some embodiments, the macro layer 124 and the plurality of optical repeating units 10 are co-extruded and co-stretched with each other. In some embodiments, the macro layer 124 has an average thickness greater than about 500 nm (or within the range described elsewhere herein), and each ORU has an average thickness less than about 1500 nm (or within the range described elsewhere herein), and includes at least a polymer A layer and different polymer B layers. In some embodiments, each layer of each optical repeating unit 10 has an average thickness less than the average thickness of the macro layer 124 or less than about 0.8 times, 0.6 times, 0.5 times, 0.4 times, or 0.3 times the average thickness of the macro layer.

[0052] In some embodiments, each of the A layers of the plurality of optical repeating units 10 has the same first composition, and each of the B layers of the plurality of optical repeating units 10 has the same second composition different from the first composition. In some embodiments, the A layer is substantially birefringent (e.g., for at least one wavelength in the range of about 450 nm to about 1500 nm, the birefringence is greater than about 0.05, 0.07, 0.1, 0.15, or 0.2; the birefringence may be, for example, at most about 0.4, 0.35, or 0.3), and the B layer is substantially optically isotropic (e.g., for at least one wavelength in the range of about 450 nm to about 1500 nm, the birefringence is less than about 0.04, 0.03, 0.02, 0.015, 0.01, or 0.008). In some embodiments, for at least one wavelength in the range of about 450 nm to about 1500 nm, the A layer and the B layer have correspondingly higher and lower average in-plane refractive indices. The in-plane refractive index is the refractive index along the direction within the plane (xy plane) of the optical film 300. In the case of a curved film, the plane of the film can be understood as a sectional plane. The average in-plane refractive index is the average value over all directions or two principal directions within the plane of the layer. In some embodiments, for at least one wavelength in the range of about 450 nm to about 1500 nm, the average in-plane refractive index of layer A may be at least about 0.05, 0.07, 0.1, 0.15, or 0.2 higher than that of layer B. The difference in average in-plane refractive index may be, for example, at most about 0.4, 0.35, or 0.3. The at least one wavelength may be or include, for example, a wavelength of about 633 nm.

[0053] Suitable materials for the various layers of the optical film 300 include, for example, polyethylene naphthalate (PEN), polyethylene terephthalate (PET), polybutylene terephthalate (PBT), polycarbonate, polymethyl methacrylate (PMMA), copolyesters, and blends or copolymers thereof. Suitable copolymers of PEN include coPEN 90 / 10 (also known as low-melting-point PEN or LmPEN) as described in U.S. Patent No. 6,946,188 (Hebrink et al.). CoPEN 90 / 10 can be described as a copolyester in which the carboxylate ester units comprise 90 mol% naphthalate ester units and 10 mol% terephthalate ester units. More generally, the copolyester may comprise other ratios of naphthalate ester units and terephthalate ester units. For example, in some embodiments, the carboxylate ester units of the coPEN copolyester may comprise about 60 mol% to 95 mol% naphthalate ester units and about 5 mol% to 40 mol% terephthalate ester units. Such copolyesters can be represented as coPENN / 100-N, where N is the molar percentage of naphthalene ester units and 100-N is the molar percentage of terephthalate ester units. In some embodiments, for example, PEN or LmPEN can be used as a high refractive index layer and / or birefringent layer (e.g., layer A), and PMMA or optically isotropic coPEN can be used as a low refractive index layer and / or optically isotropic layer (e.g., layer B). As another example, PET can be used as a high refractive index layer and / or birefringent layer (e.g., layer A), and coPMMA can be used as a low refractive index layer and / or optically isotropic layer (e.g., layer B). Other suitable materials are described in the multilayer optical film references provided elsewhere herein.

[0054] In some embodiments, the optical film 300 is or includes a reflective polarizer. In some embodiments, for substantially perpendicular incident light (e.g., with an incident angle θ less than about 30 degrees, 25 degrees, 20 degrees, 15 degrees, 10 degrees, or 8 degrees), the reflective polarizer reflects at least 60% of the incident light polarized in a first in-plane direction (e.g., the x-direction) and transmits at least 60% of the incident light polarized in an orthogonal second in-plane direction (e.g., the y-direction). In some embodiments, for substantially perpendicular incident light, the reflective polarizer reflects at least 70%, 80%, or 90% of the incident light polarized in the first in-plane direction and transmits at least 70%, 80%, or 85% of the incident light polarized in the second in-plane direction. In some embodiments, the optical film 300 is or includes an optical mirror or a partial mirror. In some implementations, for substantially perpendicular incident light, an optical mirror or partial mirror reflects at least 40%, 50%, 60%, 70%, 80%, or 90% of the incident light in each of two mutually orthogonal polarization states 101, 102.

[0055] In some embodiments, each optical repeating unit (ORU) 10 has a peak reflectivity at the corresponding resonant wavelength (RW) (see, for example...). Figure 16 The peak reflectance Rp in the optical film 300 is used to characterize the optical film 300 by the ORU thickness distribution and / or ORU RW distribution. The distribution can be determined as a function of the ORU number or depth from the same principal side (one of 301 and 302) of the optical film 300. The resonant wavelength can be determined for at least one polarization state (e.g., at least one of polarization states 101 and 102). For example, for a reflective polarizer, the resonant wavelength can be determined for a blocking polarization state. The resonant wavelength can be determined for incident light at a first (or predetermined) incident angle θ. The angle θ can be in the range of approximately 0 degrees (perpendicular incident) to about 75 degrees, 70 degrees, 65 degrees, or 60 degrees. Light can be incident on the optical film 300 from a specified medium such as air, glass, or plastic. For example, the predetermined incident angle θ can be about 45 degrees, and the specified medium can be glass or plastic. Such an incident angle and medium are suitable for describing, for example, a polarization beam splitter (PBS) comprising the optical film 300 disposed between prisms. As another example, the predetermined incident angle θ can be less than about 10 degrees, and the specified medium can be air.

[0056] Figure 2 This is a schematic diagram of the thickness or resonant wavelength (RW) of at least a portion of an optical repeating unit (ORU) of an optical film 300 according to some embodiments, relative to the ORU numbering or depth from the same main side of the optical film. Figure 2 In the middle, ORU can continue to the right, for example, as Figures 3 to 4B The illustration is shown in the figure. Figure 3 This is a schematic diagram of the ORU thickness or RW relative to the ORU numbering or depth from the same main side of the optical film 300, according to some implementation schemes. Figures 4A to 4B This is a schematic diagram of the ORU thickness or RW of at least a portion of an optical film 300 according to some embodiments, relative to the ORU numbering or depth from the same main side surface of the optical film 300. Figures 3 to 4B In each of the ORUs, the first plurality of ORUs has a range between the ranges of the other ORUs (e.g., d1 and d3). Figure 4B The thickness or RW within the range d2 schematically illustrated in the diagram, wherein the first plurality of ORUs are disposed adjacent to the first main side surface (e.g., 301) of the optical film 300. In other embodiments, the first plurality of ORUs are disposed adjacent to the opposite second main side surface (e.g., 302) of the optical film 300. Figures 5A to 5BThis is a schematic diagram of the ORU thickness or RW of at least a portion of the optical film 300 according to some embodiments, relative to the ORU numbering or depth from the same main side of the optical film 300. Schematic diagrams of ORU thickness relative to ORU numbering and ORU RW relative to depth can, for example, appear generally similar, such that the same schematic diagram can show the ORU thickness or RW along the vertical axis and the ORU numbering or depth along the horizontal axis. Lines 24 and 25 refer to lines in a scatter plot of ORU thickness or RW relative to ORU numbering or depth.

[0057] The ORU profile can be selected such that for incident light incident on the optical film at a first incident angle and for at least one polarization state (e.g., at least one of 101 and 102), within a predetermined wavelength range (e.g., in the case of...), the ORU profile is... Figures 13 to 14 (In the wavelength range of W1 to W6, which are schematically illustrated in the diagram), the reflection depth of the optical film from the same first principal side 301 of the optical film 300 varies with increasing wavelength of the incident light rather than monotonically. For example, in Figures 3 to 4B In this context, the ORU can be selected such that, starting from the first main side surface of the optical film 300 (the side surface with a lower ORU number or depth), the reflection depth for green wavelengths is less than the reflection depths for blue and red wavelengths (e.g., as shown in the image). Figure 14 (illustrative example in the text), while Figures 5A to 5B In this configuration, the ORU can be selected such that, starting from the first principal side of the optical film 300, the reflection depth for blue and red wavelengths is similar and less than the reflection depth for green wavelength (e.g., as shown in the image). Figure 13 (Illustratively illustrated). In some embodiments, the predetermined wavelength range is a visible wavelength range extending from about 400 nm to about 700 nm or from about 420 nm to about 680 nm.

[0058] According to some implementations, it has been found that using multiple stacks of ORUs of the same thickness or RW range can be advantageously used to produce similar reflection depths for the entire or substantially the entire RW range. For example, in Figure 4B In some embodiments, group 34 of ORU 10 (which includes stacks 34a, 34b, and 34c) can provide a substantially uniform depth of reflection for wavelengths substantially across the entire range d2, while groups 31 to 33 and 135 to 137 of ORU 10 can provide a substantially uniform depth of reflection for wavelengths substantially across the entire ranges d1 and d3. In some embodiments, multiple stacks are arranged from the same main side of optical film 300 to reduce the slope between stacks and / or increase the number of ORUs in the stack (see, for example...). Figures 6 to 12BAccording to some implementations, it has been found that reducing the slope and / or increasing the number of ORUs in the stack provides a more uniform reflection depth because this makes the reflectivity of stacks closer to the same main side lower than that of stacks farther away from the same main surface, so that different stacks reflect light of similar intensity, taking into account the light reflected by stacks closer to the same main side.

[0059] In some implementations, the plurality of ORUs 10 includes at least three first ORUs (e.g., Figure 2 or Figure 4A z1 to z3 in; or Figure 4A or Figure 5A (one of x1 to x3 or y1 to y3), where each first ORU has in the same first thickness (e.g., Figure 2 or Figure 4A 'a' in the middle; or Figure 4A or Figure 5AThe thickness of each first ORU (either a1 or a2) differs from the first thickness by less than P1%, and each first ORU is separated from each other by at least one ORU or at least 2, 3, 4, 5, 6, 7, 8, 10, 12, 15, or 20 ORUs, each ORU having a thickness greater than P1% from the first thickness. In some embodiments, P1% is at least about 1%, 1.5%, or 2%. In some such embodiments, or in other embodiments, P1% does not exceed about 10%, 8%, 6%, 5%, 4%, 3%, 2.5%, or 2%. For example, in some embodiments, P1% is in the range of about 1% to about 10%, or about 1% to about 5%, or about 1% to about 4%, or about 1% to about 3%, or about 1% to about 2%, or about 1.5% to about 8%, or about 2% to about 6%, or about 2% to about 4%, or about 2% to about 3%. In some embodiments, P1% is approximately 1%, 1.5%, 2%, 2.5%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, or 10%. In some embodiments, the thickness of each of the at least three first RUs is within 2.5% of the first thickness, and the thickness of at least one ORU separating the first ORU, or each of at least two, three, four, five, six, seven, eight, ten, twelve, fifteen, or twenty ORUs, differs from the first thickness by more than 3%. In some such embodiments, or in other embodiments, the thickness of each of the at least three first RUs is within 2%, 1.5%, or 1% of the first thickness. In some such embodiments, or in other embodiments, the thickness of at least one ORU, or each of at least two, three, four, five, six, seven, eight, ten, twelve, fifteen, or twenty ORUs, differs from the first thickness by more than 3.5%, 4%, or 4.5%. In some implementations, each first ORU is separated from each other by at least one ORU or at least 2, 3, 4, 5, 6, 7, 8, 10, 12, 15, or 20 ORUs, each ORU having a difference from the first thickness greater than P1% + 0.5%, or P1% + 1%, P1% + 1.5%, P1% + 2%, P1% + 2.5%, P1% + 3%, P1% + 3.5%, P1% + 4%, P1% + 4.5%, P1% + 5%, P1% + 6%, P1% + 7%, P1% + 8%, P1% + 9%, or P1% + Thicknesses that are 10% or greater than P1% by 1.01, 1.03, 1.05, 1.07, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.8 or 2 times.For example, in some embodiments, the thickness of each ORU in the at least one ORU differs from the first thickness by more than P1% + 0.5%, where P1% is in the range of about 1% to about 3%. As another example, in some embodiments, each first ORU is separated from each other first ORU by at least two ORUs, each ORU having a thickness that differs from the first thickness by more than P1% + 1%.

[0060] In some implementations, the plurality of ORUs 10 includes at least three second ORUs (e.g., Figure 4A or Figure 5A Each second ORU has a thickness within P1% of the same second thickness (e.g., the other of a1 or a2), and each second ORU is separated from the first ORU by at least one ORU or at least 2, 3, 4, 5, 6, 8, 10, 12, 15, or 20 ORUs, each ORU having a thickness greater than P1% of the second thickness. In some embodiments, the second thickness differs from the first thickness by at least about 10 nm, 15 nm, 20 nm, 30 nm, 40 nm, 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm. In some embodiments, the second thickness differs from the first thickness by at least about 1.2 times, 1.5 times, 1.8 times, 2 times, 2.2 times, 2.4 times, or 2.5 times P1%. Each second ORU in the second ORU is typically different from each first ORU in the first ORU. In some embodiments, the thickness of each of the at least three second ORUs is within 2.5% of the second thickness, and the thickness of at least one ORU, or each of at least two, three, four, five, six, seven, eight, ten, twelve, fifteen, or twenty ORUs, differs from the second thickness by more than 3%. In some such embodiments, or in other embodiments, the thickness of each of the at least three second ORUs is within 2%, 1.5%, or 1% of the second thickness. In some such embodiments, or in other embodiments, the thickness of at least one ORU separating the second ORU, or each of at least two, three, four, five, six, seven, eight, ten, twelve, fifteen, or twenty ORUs, differs from the second thickness by more than 3.5%, 4%, or 4.5%.

[0061] The at least three first ORUs may be or include at least four first ORUs. In some embodiments, the at least three first ORUs include up to 15, 12, 10, 8, 7, 6, 5, or 4 first ORUs. Similarly, the at least three second ORUs may be or include at least four second ORUs. In some embodiments, the at least three second ORUs include up to 15, 12, 10, 8, 7, 6, 5, or 4 second ORUs.

[0062] The optical film 300 can be characterized by the ORU thickness as described above and / or elsewhere herein. Alternatively or otherwise, the optical film 300 can be characterized by the resonant wavelength of the ORU.

[0063] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, such that for incident light 100 incident on the optical film at a first incident angle θ and for at least one polarization state (e.g., at least one of 101 and 102): each ORU in the ORU 10 has a peak reflectivity at a corresponding resonant wavelength (RW) in the range of about 300 nm to about 3000 nm; for a first wavelength (e.g., a, a1, or a2—see example) set in the visible wavelength range extending from about 420 nm to about 680 nm. Figure 2 , Figure 4A , Figure 5AThe optical film 300 includes at least three first ORUs (e.g., z1 to z3, x1 to x3, or y1 to y3), wherein each first ORU has a range of reflection (RW) within P1% of a first wavelength, and wherein each first ORU is separated from each other by at least one ORU or at least two, three, four, five, six, seven, eight, ten, twelve, fifteen, or twenty ORUs, each ORU having an RW greater than P1% of the first wavelength; and in the visible wavelength range, the reflection depth of the optical film from the same first principal side of the optical film varies rather than monotonically with increasing wavelength of the incident light. In some embodiments, P1% is in the range of about 1% to about 10%, or P1% may be in any range described elsewhere herein. In some embodiments, the RW of each ORU is at least about 320 nm, 340 nm, 360 nm, 380 nm, or 400 nm. In some such embodiments, or in others, the RW of each ORU does not exceed about 2500 nm, 2000 nm, 1500 nm, 1200 nm, 1000 nm, 900 nm, 800 nm, or 750 nm. In some embodiments, for incident light 100 incident on the optical film at a first incident angle θ and for at least one polarization state: for a second wavelength (e.g., a2) differing from the first wavelength (e.g., a1) by at least 50 nm, 100 nm, or 150 nm and set within the visible wavelength range, the optical film 300 includes at least three second ORUs (e.g., y1 to y3), wherein each second ORU has an RW within P1% of the second wavelength. In some embodiments, each second ORU is separated from each other by at least one ORU or at least 2, 3, 4, 5, 6, 7, 8, 10, 12, 15, or 20 ORUs, each ORU having an RW greater than P1% of the second wavelength.

[0064] The percentage difference between the RW of the first (or second) ORU and the first (or second) wavelength, and the percentage difference between the RW of ORUs located between the first (or second) ORUs, can be within any of the corresponding ranges described for ORU thickness. For example, in some embodiments, the RW of each of the at least three first ORUs is within 2.5%, 2%, 1.5%, or 1% of the first wavelength, and the RW of each of at least one ORU differs from the first wavelength by more than 3%. In some such embodiments, or in other embodiments, the RW of each of the at least one ORU differs from the first wavelength by more than 3.5%, 4%, or 4.5%. In some embodiments, each first ORU is separated from each other first ORU by at least one ORU having an RW that differs from the first wavelength by more than P1% + 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, or 10%. In some embodiments, each first ORU is separated from each other first ORU by at least 2, 3, 4, 5, 6, or 7 ORUs, wherein each of the at least 2, 3, 4, 5, 6, or 7 ORUs has a range of wavelengths (RW) greater than P1% from the first wavelength. In some embodiments, each of the at least 2, 3, 4, 5, 6, or 7 ORUs has an RW greater than P1% + 0.5%, 1%, 1.5%, 2%, 2.5%, 3%, 3.5%, 4%, 4.5%, 5%, 6%, 7%, 8%, 9%, or 10% from the first wavelength.

[0065] In some embodiments, as further described elsewhere herein, for incident light 100 incident on optical film 300 at a first incident angle θ and for at least one polarization state (e.g., 101 and / or 102), within a predetermined wavelength range (e.g., a visible wavelength range of about 400 nm to about 700 nm, or about 420 nm to about 680 nm), the reflection depth of optical film 300 from the same first principal side surface (e.g., 301) of optical film 300 varies rather than monotonically with increasing wavelength of the incident light. In some embodiments, for incident light 100 incident on optical film at a first incident angle θ and for at least one polarization state: the plurality of ORUs 10 have a first average reflection depth F1, a second average reflection depth F2, and a third average reflection depth F3 relative to the same first principal side surface 301 of optical film 300 within corresponding non-overlapping first wavelength ranges, second wavelength ranges, and third wavelength ranges (W1 to W2, W3 to W4, and W5 to W6) (see, for example...). Figures 13 to 14The second wavelength range is set between the first wavelength range and the third wavelength range. In some embodiments, the second average reflection depth F2 differs from each of the first average reflection depth F1 and the third average reflection depth F3 by (e.g., V2) at least about 1.2 times, 1.25 times, 1.3 times, 1.35 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2 times, 2.25 times, 2.5 times, 2.75 times, 3 times, 3.5 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, or 10 times. In some embodiments, the second average reflection depth F2 is less than about 10 micrometers, 9 micrometers, 8 micrometers, 7.5 micrometers, 7 micrometers, 6.5 micrometers, 6 micrometers, 5.5 micrometers, 5 micrometers, 4.5 micrometers, or 4 micrometers.

[0066] In some embodiments, as further described elsewhere herein, the plurality of ORUs 10 are disposed on the same first primary surface 124a of a macroscopic layer 124 having an average thickness greater than about 500 nm (or within the range described elsewhere herein). In some embodiments, for incident light 100 incident on the optical film 300 at a first incident angle θ and for at least one polarization state: for a first wavelength within a predetermined wavelength range (e.g., Figure 14 W7 in; or Figure 13 Between W1 and W2 or between W5 and W6; and / or a, a1, or a2—see example Figure 2 , Figure 4A , Figure 5AThe plurality of ORUs have a reflection depth relative to the first master surface of the macroscopic layer of less than about 10 micrometers, 9 micrometers, 8 micrometers, 7.5 micrometers, 7 micrometers, 6.5 micrometers, 6 micrometers, 5.5 micrometers, 5 micrometers, 4.5 micrometers, or 4 micrometers. The reflection depth may be, for example, at least about 0.25 micrometers, 0.5 micrometers, 1 micrometer, or 1.5 micrometers. The first wavelength may be, for example, a green wavelength in the range of about 490 nm to about 560 nm (e.g., about 525 nm). In some embodiments, for incident light incident on the optical film at a first incident angle and for at least one polarization state: for a wavelength range at least 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, or 60 nm wide and substantially centered on the first wavelength (e.g., the first wavelength may be closer to the center of the wavelength range than to any edge of the wavelength range), the plurality of ORUs have an average reflectivity greater than about 60%, 70%, 80%, 85%, 90%, or 95%. The wavelength range can be, for example, from about 490 nm to about 560 nm. In some embodiments, the wavelength range extends between a first end wavelength and a second end wavelength, and has a center wavelength that is the average of the first end wavelength and the second end wavelength. In some embodiments, the absolute value of the difference between the first wavelength and the center wavelength is less than about 25%, 20%, 15%, 10%, or 5% of the absolute value of the difference between the first end wavelength and the second end wavelength. In some embodiments, the first wavelength is equal to or approximately equal to the center wavelength.

[0067] Optical film 300 may optionally include Figures 2 to 5B Additional ORU 10 groups are not shown. For example, one or more ORU groups may optionally be set. Figure 4A Between ORU 36f and 37a, or set in Figure 4A After ORU 36c (higher ORU numbers or depths), or set in Figure 5B Between group 33 and ORU 39 in the diagram. Additional ORU groups may include at least one group for reflection in different wavelength ranges (e.g., different from d1, d2, d3), and / or may include at least one additional group for reflection in the same range as one or more of the illustrated groups (e.g., one or more of d1, d2, d3).

[0068] Figure 6 It is a diagram of the resonant wavelength relative to the depth from the same main side of the optical film 300 according to some implementation schemes. Figure 6 Examples of non-overlapping figures are shown in Figures 190 to 194 and 190' to 193'. Figure 7 It shows the Figure 6The resonant wavelength is used to perform a polynomial fit (best quadratic fit) on the corresponding non-overlapping graphs 190 to 193 for the depth portion of the graph. Similar polynomial fits can be constructed for the non-overlapping graphs 190' to 193' and 194. Figure 8 yes Figure 7 The corresponding fitting plot of slopes from 190a to 193a and from 190b to 193b against the resonant wavelength. Figure 6 The resonant wavelength is determined for light incident on the optical film from a glass having a refractive index of about 1.8 at the visible wavelength (e.g., about 633 nm).

[0069] Figure 9 Figure a shows the ORU numbering based on the ORU thickness of the optical film 300 according to some implementation schemes. Figure 6 and Figure 9 The diagram can be for the same optical film. Figure 9 Examples of non-overlapping diagrams 90 to 94 and 90' to 93' are shown in the middle. Figure 10 It shows the Figure 9 The ORU thickness is linearly fitted to the corresponding non-overlapping plots 90 to 93 for the portion of the ORU numbered plot. Similar linear fits can be constructed for non-overlapping plots 90' to 93' and 94.

[0070] Figure 11A It is a diagram of the resonant wavelength relative to the depth from the same main side of the optical film, based on some implementation schemes. Figure 11B yes Figure 11A Part of the diagram. Figure 12A This is a diagram showing the ORU numbering based on the ORU thickness of some implementation schemes. Figure 12B yes Figure 12A Part of the diagram. Figures 11A to 11B and Figures 12A to 12B The diagram can be for the same optical film.

[0071] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, which are sequentially numbered from the same first main side 301 of the optical film 300 to the opposite second main side 302 of the optical film 300, such that for a first thickness range of at least about 20 nm wide (e.g., Figure 5B d1 or d3 or Figure 4B The thickness of the ORUs in the scatter plot 20 includes at least a first non-overlapping plot, a second non-overlapping plot, and a third non-overlapping plot of the sequentially numbered ORUs (e.g., d1, d2, or d3). Figure 9 90 to 93 and / or 90' to 94' or Figure 12B(90 to 93) wherein each ORU of each non-overlapping map in at least the first, second, and third non-overlapping maps has a thickness within a first thickness range, and wherein each non-overlapping map in at least the first, second, and third non-overlapping maps includes at least 2, 3, 4, 5, 6, or 7 ORUs from the plurality of ORUs 10. In some embodiments, the slope of the best linear fit for at least two non-overlapping maps in at least the first to third non-overlapping maps (e.g., Figure 10 The magnitudes of the best linear fits (90a to 93a, having corresponding slopes of approximately 9.5 nm, 65 nm, 1.7 nm, and 0.85 nm per ORU number) differ by at least approximately 20%, 30%, 40%, 50%, 75%, 100%, 250%, and 500%, or by at least approximately 5, 6, 7, 8, 9, 10, or 11 times. In some embodiments, the first thickness range is at least approximately 30 nm, 40 nm, or 50 nm wide. The first thickness range may be, for example, at most approximately 200 nm, 150 nm, 100 nm, or 75 nm wide.

[0072] In some implementations, for a second thickness range that is at least about 20 nm wide and does not overlap with the first thickness range (e.g., Figure 5B d1 or d3 or Figure 4B (different from d1, d2, or d3 in the original text), the ORU thickness scatter plot 20 includes at least a fourth, fifth, and sixth non-overlapping plots of the sequentially numbered ORUs (e.g., ... Figure 9 90 to 93 and / or 90' to 94' or Figure 12B (different from 90 to 93 in the plurality of ORUs), wherein each ORU of each non-overlapping map in at least the fourth, fifth, and sixth non-overlapping maps has a thickness within the second thickness range, and wherein each non-overlapping map in at least the fourth, fifth, and sixth non-overlapping maps includes at least 2, 3, 4, 5, 6, or 7 ORUs from the plurality of ORUs 10. In some embodiments, the magnitudes of the slopes of the best linear fits for at least two of the at least fourth to sixth non-overlapping maps differ by at least about 20%, 30%, 40%, 50%, 75%, 100%, 250%, or 500%, or by at least about 5, 6, 7, 8, 9, 10, or 11 times. The width of the second thickness range may be within any of the ranges described elsewhere herein with respect to the width of the first thickness range.

[0073] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, wherein each ORU has a peak reflectivity at a corresponding resonant wavelength (RW), such that for a first wavelength range at least about 40 nm wide (e.g., Figure 5B d1 or d3 or Figure 4B The RW of the ORU relative to the depth of the ORU relative to the same principal side (e.g., 301) of the optical film 300 includes at least a first non-overlapping map, a second non-overlapping map, and a third non-overlapping map of the ORU (e.g., d1, d2, or d3 in the original text). Figure 6 190 to 193 and / or 190' to 194' or Figure 11B (190 to 193), wherein each ORU of at least the first, second, and third non-overlapping maps has a RW within a first wavelength range, and wherein each non-overlapping map of at least the first, second, and third non-overlapping maps includes at least 2, 3, 4, 5, 6, or 7 ORUs from the plurality of ORUs and has as being in the same first RW (e.g., Figure 8 The slope of the rate of change of RW relative to depth (i.e., d(RW) / d(depth)) at the first RW 95) in the middle (e.g., Figure 8 (190b to 193b in the original text). The slope can be fitted from the best polynomial (e.g., quadratic) (e.g., ... Figure 7 The optimal quadratic fit (190a to 193a) is determined. In some embodiments, the slope magnitudes of at least two of the first to third plots (e.g., slope magnitudes of approximately 62, 42, 11, and 5.5 at the first RW95) differ by at least approximately 20%, 30%, 40%, 50%, 75%, 100%, 250%, or 500%, or by at least approximately 5, 6, 7, 8, 9, 8, 9, 10, or 11 times. The slope magnitudes may differ by, for example, up to approximately 50, 40, 30, 20, or 15 times. In some embodiments, the first wavelength range is at least approximately 50 nm, 60 nm, 70 nm, 80 nm, 90 nm, or 100 nm wide. The first wavelength range may be, for example, up to approximately 500 nm, 400 nm, 300 nm, 200 nm, or 150 nm.

[0074] In some implementations, for a second wavelength range that is at least about 40 nm wide and does not overlap with the first wavelength range (e.g., Figure 5B d1 or d3 or Figure 4B The RW of the ORU relative to the depth of the ORU relative to the same principal side (e.g., 301) of the optical film 300 includes at least a fourth, fifth, and sixth non-overlapping plot of the ORU (e.g., one of d1, d2, or d3). Figure 6 190 to 193 and / or 190' to 194' or Figure 11B (another of 190 to 193), wherein each ORU of each non-overlapping map in at least the fourth, fifth, and sixth non-overlapping maps has an RW in the second wavelength range, and wherein each non-overlapping map in at least the fourth, fifth, and sixth non-overlapping maps includes at least 2, 3, 4, 5, 6, or 7 ORUs from the plurality of ORUs and has as being in the same first RW (e.g., Figure 8 The slope of the rate of change of RW relative to depth (i.e., d(RW) / d(depth)) at the first RW 95) in the middle (e.g., Figure 8 (Figures 190b to 193b). In some embodiments, the slope amplitudes of at least two figures in at least the fourth to sixth figures differ by at least about 20%, 30%, 40%, 50%, 75%, 100%, 250%, or 500%, or by at least about 5, 6, 7, 8, 9, 8, 9, 10, or 11 times. The slope amplitudes may differ by, for example, up to about 50, 40, 30, 20, or 15 times. The width of the second wavelength range may be within any of the ranges described elsewhere herein with respect to the width of the first wavelength range.

[0075] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, wherein each ORU has a peak reflectivity at a corresponding resonant wavelength (RW), such that when adjacent data points are connected by straight line segments to form a continuous line plot in a scatter plot 20 of the RW of the ORUs relative to the depth of the ORUs on the same principal side (e.g., 301) of the optical film 300, the continuous line plot includes a plurality of first lines (e.g., Figure 3 , Figure 4A or Figure 5A The first line 24), the multiple first lines and multiple second lines (e.g., Figure 3 , Figure 4A or Figure 5A The second lines 25 in the diagram alternate and intersect, in which the ORU RW in all first lines substantially increases with the same condition of increasing or decreasing ORU depth, and in which the ORU RW in all second lines substantially decreases with the same condition of increasing or decreasing ORU depth (note that the ORU number or depth can be counted from the opposite main side of the optical film 300 from any of the illustrated diagrams, such that each line in which the ORU thickness or RW increases with increasing ORU number or depth becomes a line in which the ORU thickness or RW increases with decreasing ORU number or depth). The intersections can form multiple alternating peaks and valleys (e.g., Figure 4A or Figure 5A36a to 36c and 37a to 37c in the middle; Figure 3 or Figure 4A (36d to 36f and 37d to 37f in the example). In some embodiments, the first first line of the plurality of first lines 24 includes a plurality of first straight line segments extending from the first valley (e.g., 37b) of the plurality of alternating peaks and valleys to the first peak (e.g., 36b) of the plurality of alternating peaks and valleys (i.e., the first straight line segments extend from the first valley to the first peak in combination), wherein the slope of the first straight line segment has a minimum and a maximum slope magnitude (e.g., the minimum and maximum slope magnitudes may appear in the example). Figure 4A or Figure 5A The corresponding line segments 24a and 24b in the middle or Figure 6 (On the corresponding straight line segment in the diagram). In some embodiments, the minimum slope amplitude is at least about 5 nm / µm, 6 nm / µm, 8 nm / µm, 10 nm / µm, 12 nm / µm, 15 nm / µm, 20 nm / µm, 25 nm / µm, 30 nm / µm, or 35 nm / µm. In some such embodiments, or in other embodiments, the maximum slope amplitude is at least about 3, 5, 7, 10, 12, 15, 20, or 25 times the minimum slope amplitude. The minimum slope amplitude can be, for example, at most about 400 nm / µm, 300 nm / µm, 250 nm / µm, 200 nm / µm, 150 nm / µm, or 100 nm / µm. The maximum slope amplitude can be, for example, at most about 500, 250, 200, 150, 100, 80, 60, or 50 times the minimum slope amplitude. In some embodiments, the maximum slope amplitude is in the range of, for example, about 150 nm / µm to 600 nm / µm. In some embodiments, the plurality of alternating peaks and valleys may include an alternating arrangement of at least three peaks and at least two valleys. In some embodiments, at least two of the plurality of first lines are substantially parallel (e.g., slopes of corresponding ORU thicknesses or RWs with the same sign, and whose amplitudes are within about 30%, 20%, 10%, or 5% of each other). In some embodiments, at least two of the plurality of second lines are substantially parallel. For example, in Figure 3 In the middle, the first three first lines 24 (from 37d to 36d; from 37e to 36e; and from 37f to 36f) are essentially parallel, and the first two second lines 25 (from 36d to 37e; and from 36e to 37f) are essentially parallel. As another example, in Figure 5A In the middle, the first three first lines 24 (from 37a to 36a; from 37b to 36b; and from 37c to 36c) are essentially parallel, and the first two second lines 25 (from 36a to 37b; and from 36b to 37c) are essentially parallel. Similarly, for example... Figure 6 and Figure 9The first two first lines 24 and the first two second lines 25 are substantially parallel. In some embodiments, at least one of the first straight segments (e.g., the first straight segment 24b with the maximum slope) extends over an ORU RW range of at least about 40 nm, 50 nm, 60 nm, 70 nm, 75 nm, or 80 nm. The ORU RW range may be, for example, up to about 400 nm, 300 nm, 250 nm, 200 nm, 175 nm, 150 nm, or 125 nm.

[0076] Other lines in the first line may have similar minimum and maximum slope amplitudes. For example, in some embodiments, a second first line among multiple first lines, distinct from the first first line, comprises multiple second straight line segments extending from a second valley (distinct from the first valley) in the multiple alternating peaks and valleys to a second peak (distinct from the first peak) in the multiple alternating peaks and valleys, wherein the slope of the second straight line segment includes a second minimum slope amplitude and a second maximum slope amplitude. The second minimum slope amplitude may be at least about 5 nm / micrometer (or within another range described with respect to the minimum slope amplitude), and the second maximum slope amplitude may be at least about 3 times the second minimum slope amplitude (or within another range described with respect to the ratio of the maximum slope amplitude to the minimum slope amplitude).

[0077] The terms "substantially increase" and "substantially decrease" should be understood to mean an increase or decrease in a general sense with changes in ORU number or ORU depth, while allowing for noise and / or process variations that may deviate from the general trend. That is, while RW or thickness can generally increase or decrease with changes in ORU number or depth, one or more pairs of adjacent plot points may move in the opposite direction to the overall trend. In the context of a continuous line plot formed by straight line segments between data points in a scatter plot of ORU thickness or RW against ORU number or depth, the term "line" should be understood as a set of adjacent straight line segments in which the ORU thickness or RW in the line segments substantially increases with both increases and decreases in ORU number or depth. For example, in Figure 4A and Figure 5A In the middle, the line 24 between valley 37b and peak 36b includes straight segments 24a and 24b. In this context, "line" can be a straight line or an approximately straight line, or it can be a non-linear line (e.g., curved and / or including one or more bends).

[0078] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, which are sequentially numbered from the same first main side 301 of the optical film 300 to the opposite second main side 302 of the optical film 300, such that when adjacent data points in a scatter plot 20 of the ORU thicknesses are connected by straight line segments to form a continuous line plot, the continuous line plot includes a plurality of first lines (e.g., Figure 3 , Figure 4A or Figure 5A The first line 24), the multiple first lines and multiple second lines (e.g., Figure 3 , Figure 4A or Figure 5A The second line 25 in the multiple first lines alternates and intersects. In all the first lines, the ORU thickness increases substantially with the same increase and decrease in ORU number, while in all the second lines, the ORU thickness decreases substantially with the same increase and decrease in ORU number. The intersections can form multiple alternating peaks and valleys (e.g., Figure 4A or Figure 5A 36a to 36c and 37a to 37c in the middle; Figure 3 or Figure 4A (36d to 36f and 37d to 37f in the example). In some embodiments, one of the first lines 24 comprises a plurality of first straight line segments (e.g., 24a, 24b) extending from the first valley (e.g., 37b) of the plurality of alternating peaks and valleys to the first peak (e.g., 36b) of the plurality of alternating peaks and valleys, wherein the slope of the first straight line segment includes minimum and maximum slope magnitudes (e.g., the minimum and maximum slope magnitudes may appear in the example). Figure 4A or Figure 5A The corresponding first straight segments 24a and 24b in the middle or Figure 9(corresponding to the first straight line segment). In some embodiments, the minimum slope amplitude is at least about 0.5nm, 0.7nm, 0.9nm, 1nm, 1.1nm, 1.2nm, 1.3nm, 1.5nm, 1.7nm, 2nm, 2.5nm, 3nm, 4nm, 5nm, or 6nm per ORU number. In some such embodiments, or in other embodiments, the maximum slope amplitude is at least about 3, 5, 7, 10, 12, 15, 20, or 25 times the minimum slope amplitude. The minimum slope amplitude may be, for example, at most about 100nm, 80nm, 60nm, 40nm, 30nm, 20nm, or 15nm per ORU. The maximum slope amplitude may be, for example, at most about 500, 250, 200, 150, 100, 80, 60, or 50 times the minimum slope amplitude. In some embodiments, the maximum slope amplitude is in the range of, for example, about 20 nm to 100 nm per ORU. In some embodiments, the plurality of alternating peaks and valleys may include an alternating arrangement of at least three peaks and at least two valleys. In some embodiments, at least two of the plurality of first lines are substantially parallel. In some embodiments, at least two of the plurality of second lines are substantially parallel. In some embodiments, at least one of the first straight segments (e.g., the first straight segment 24b with the maximum slope) extends over an ORU thickness of at least about 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, or 50 nm. The ORU thickness range may be, for example, up to about 300 nm, 200 nm, 150 nm, 100 nm, or 75 nm.

[0079] Other lines in the first line may have similar minimum and maximum slope amplitudes. For example, in some embodiments, a second first line among multiple first lines, distinct from the first first line, comprises multiple second straight line segments extending from a second valley (distinct from the first valley) in the multiple alternating peaks and valleys to a second peak (distinct from the first peak) in the multiple alternating peaks and valleys, wherein the slope of the second straight line segment includes a second minimum slope amplitude and a second maximum slope amplitude. The second minimum slope amplitude may be at least about 0.5 nm per ORU number (or within another range described for the minimum slope amplitude), and the second maximum slope amplitude may be at least about 3 times the minimum slope amplitude (or within another range described for the ratio of the maximum slope amplitude to the minimum slope amplitude).

[0080] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, each ORU having a peak reflectivity at a corresponding resonant wavelength (RW), such that when adjacent data points are connected by straight line segments to form a continuous line graph in a scatter plot 20 of the RW of the ORUs relative to the depth of the ORUs on the same principal side (e.g., 301) of the optical film 300, the continuous line graph includes a plurality of first lines 24 that alternate and intersect with a plurality of second lines 25, wherein the RW of the ORUs in all the first lines substantially increases with the same condition of increasing or decreasing ORU depth, and the RW of the ORUs in all the second lines substantially decreases with the same condition of increasing or decreasing ORU depth. The intersections may form at least a plurality of alternating peaks and valleys (e.g., Figure 3 or Figure 4A In some embodiments, for each pair of adjacent peaks and valleys in the first plurality of alternating peaks and valleys (e.g., 36d and 37e; or 36e and 37f), the difference in the ORU RW between the peaks and valleys is greater than about 5 nm and less than about 200 nm. In some embodiments, for each pair of adjacent peaks and valleys in the first plurality of alternating peaks and valleys, the difference in the ORU RW between the peaks and valleys is greater than about 6 nm, 7 nm, 8 nm, 0 nm, 10 nm, 12 nm, 15 nm, 20 nm, 25 nm, or 30 nm. In some such embodiments, or in other embodiments, for each pair of adjacent peaks and valleys in the first plurality of alternating peaks and valleys, the difference in the ORU RW between the peaks and valleys is less than about 180 nm, 160 nm, 140 nm, 120 nm, 100 nm, 90 nm, 80 nm, or 70 nm. For a pair of adjacent peaks and valleys considered as a plurality of alternating peaks and valleys, there should be no peaks and valleys situated between the pair. In some embodiments, the intersection forms a second plurality of alternating peaks and valleys that do not overlap with the first plurality of alternating peaks and valleys (e.g., Figure 4A (36a to 36c and 37a to 37c in the second plurality of alternating peaks and valleys). In some embodiments, for at least one pair of adjacent peaks and valleys in the second plurality of alternating peaks and valleys (e.g., 36a and 37b), the difference in the ORU RW between the peak and valley is greater than about 200 nm, 220 nm, 240 nm, 260 nm, or 280 nm. In some embodiments, for each pair of adjacent peaks and valleys in the second plurality of alternating peaks and valleys, the difference in the ORU RW between the peak and valley is greater than about 200 nm, 220 nm, 240 nm, 260 nm, or 280 nm. This difference may be, for example, up to about 3000 nm, 2500 nm, 2000 nm, 1500 nm, 1000 nm, 800 nm, 600 nm, 500 nm, or 400 nm.

[0081] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, which are sequentially numbered from the same first principal side 301 of the optical film 300 to the opposite second principal side 302 of the optical film 300, such that when adjacent data points in a scatter plot 20 of the ORU thicknesses are connected by straight line segments to form a continuous line plot, the continuous line plot includes a plurality of first lines 24 that alternate and intersect with a plurality of second lines 25, in which the ORU thickness in all first lines substantially increases with the same condition of increasing and decreasing ORU numbering, and in which the ORU thickness in all second lines substantially decreases with the same condition of increasing and decreasing ORU numbering. The intersections may form at least a plurality of alternating peaks and valleys (e.g., Figure 3 or Figure 4A In some embodiments, for each pair of adjacent peaks and valleys in the first plurality of alternating peaks and valleys (e.g., 36d and 37e; or 36e and 37f), the difference in ORU thickness between the peaks and valleys is greater than about 3 nm and less than about 120 nm. In some embodiments, for each pair of adjacent peaks and valleys in the first plurality of alternating peaks and valleys, the difference in ORU thickness between the peaks and valleys is greater than about 4 nm, 5 nm, 6 nm, 7 nm, 8 nm, 0 nm, 10 nm, 12 nm, 15 nm, or 20 nm. In some such embodiments, or in other embodiments, for each pair of adjacent peaks and valleys in the first plurality of alternating peaks and valleys, the difference in ORU thickness between the peaks and valleys is less than about 100 nm, 90 nm, 80 nm, 70 nm, 60 nm, 50 nm, or 40 nm. In some embodiments, the intersections form a second plurality of alternating peaks and valleys that do not overlap with the first plurality of alternating peaks and valleys. Figure 4A (36a to 36c and 37a to 37c in the second plurality of alternating peaks and valleys). In some embodiments, for at least one pair of adjacent peaks and valleys in the second plurality of alternating peaks and valleys (e.g., 36a and 37b), the difference in ORU thickness between the peaks and valleys is greater than about 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, or 150 nm. In some embodiments, for each pair of adjacent peaks and valleys in the second plurality of alternating peaks and valleys, the difference in ORU thickness between the peaks and valleys is greater than about 120 nm, 125 nm, 130 nm, 135 nm, 140 nm, 145 nm, or 150 nm. This difference may be, for example, up to about 1500 nm, 1000 nm, 750 nm, 500 nm, 400 nm, 300 nm, 250 nm, or 200 nm.

[0082] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, wherein the ORUs in the plurality of ORUs 10 are sequentially numbered from the same first principal side 301 of the optical film 300 to the opposite second principal side 302 of the optical film 300, such that for a non-overlapping first thickness range and a second thickness range of at least about 5 nm wide (e.g., Figure 4B or Figure 5BThe scatter plot 20 of ORU thickness versus numbering includes at least three non-overlapping first groups (e.g., one of 31 to 33 and 135 to 137) of sequentially numbered ORUs in the plurality of ORUs, wherein each ORU in each group of the first groups has a thickness within a first thickness range (one of d1 and d3), each group of the first groups includes at least three sequentially numbered ORUs in the plurality of ORUs, and each first group is separated from each other first group by at least two sequentially numbered ORUs in the plurality of ORUs whose thickness is not within the first thickness range. The scatter plot 20 also includes second groups (e.g., group 34 or 134) of at least 8, 10, 12, 15, 20, 30, 40, 50, 60, or 70 ORUs in the plurality of ORUs, each ORU in the second group having a thickness within a second thickness range (e.g., d2). The plurality of ORUs 10 may include a first ORU 39 and a second ORU 49, each having a thickness outside the second thickness range, wherein a second group 134 is disposed between the first ORU 39 and the second ORU 49. In some embodiments, each of the first and second thickness ranges is at least about 7 nm, 10 nm, 12 nm, 15 nm, 20 nm, 25 nm, or 30 nm wide. In some embodiments, for a third thickness range (the other of d1 and d3) that is at least about 5 nm wide and does not overlap with the first and second thickness ranges, a scatter plot of the ORU thickness-to-numbering includes at least three non-overlapping third groups (e.g., the other of 31 to 33 and 135 to 137) of sequentially numbered ORUs from the plurality of ORUs, wherein each ORU in each group of the third groups has a thickness within the third thickness range, each group of the third groups includes at least three sequentially numbered ORUs from the plurality of ORUs, and each third group is separated from each other third group by at least two sequentially numbered ORUs from the plurality of ORUs whose thickness is not within the third thickness range. In some embodiments, the third thickness range is at least about 7 nm, 10 nm, 12 nm, 15 nm, 20 nm, 25 nm, or 30 nm wide. The first, second, and / or third thickness ranges may be, for example, at most about 700 nm, 500 nm, 400 nm, 300 nm, 200 nm, 150 nm, or 100 nm wide. In some implementations, each of the first ORU 39 and the second ORU 49 has a thickness outside each of the first thickness range d1, the second thickness range d2 and the third thickness range d3.In some embodiments, the average slope magnitude of the scatter plot in each group of the first group is at least 1.2, 1.5, 2, 3, 4, 5, 6, 7, 8, 9, or 10 times the average slope magnitude of the scatter plot in the second group. The average slope magnitude is the average (unweighted mean) of the magnitudes (absolute values) of the slopes of the scatter plot (e.g., the average of the straight line segments between adjacent ORUs in the group for lines 24 and / or 25). In some embodiments, the optical film 300 does not include groups of at least 8, 10, 12, 20, 30, 40, 50, 60, 70, 80, 90, or 100 sequentially numbered ORUs, wherein each ORU in the group has a thickness within a second thickness range (e.g., d2), and wherein the group does not overlap with the second group. In some embodiments, the ORUs in the second group are sequentially numbered among the sequentially numbered ORUs. In some implementations, the ORUs in the second group are sequential to each other.

[0083] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, wherein each ORU has a peak reflectivity at a corresponding resonant wavelength (RW), and wherein the ORUs of the plurality of ORUs are sequentially numbered from the same first principal side 301 of the optical film 300 to the opposite second principal side 302 of the optical film, such that for a non-overlapping first wavelength range and second wavelength range of at least about 15 nm wide (e.g., Figure 4B or Figure 5BThe scatter plot 20 of the RW pair numbering of the ORUs includes at least three non-overlapping first groups (e.g., one of 31 to 33 and 135 to 137) of sequentially numbered ORUs in the plurality of ORUs, wherein each ORU in each group of the first groups has an RW in a first wavelength range, each group of the first groups includes at least three sequentially numbered ORUs in the plurality of ORUs, and each first group is separated from each other first group by at least two sequentially numbered ORUs in the plurality of ORUs whose RWs are not in the first wavelength range. The scatter plot 20 also includes second groups (e.g., 34 or 134) of at least 8, 10, 12, 15, 20, 30, 40, 50, 60 or 70 ORUs in the plurality of ORUs, wherein each ORU in the second group has an RW in a second wavelength range. The plurality of ORUs may include a first ORU 39 and a second ORU 49, each having a RW outside the second wavelength range, wherein a second group 134 is disposed between the first ORU 39 and the second ORU 49. In some embodiments, each wavelength range in the first and second wavelength ranges is at least about 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, or 60 nm wide. In some embodiments, for a third wavelength range (another of d1 and d3) that is at least about 15 nm wide and does not overlap with the first and second wavelength ranges, the scatter plot of the RW pair numbering of the ORUs includes at least three non-overlapping third groups (e.g., another of 31 to 33 and 135 to 137) of sequentially numbered ORUs among the plurality of ORUs, wherein each ORU in each group of the third groups has an RW within the third wavelength range, each group of the third groups includes at least three sequentially numbered ORUs among the plurality of ORUs, and each third group is separated from each other third group by at least two sequentially numbered ORUs among the plurality of ORUs whose RWs are not within the third wavelength range. In some embodiments, the third wavelength range is at least about 7 nm, 10 nm, 12 nm, 15 nm, 20 nm, 25 nm, or 30 nm wide. In some embodiments, the third wavelength range is at least about 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, or 60 nm wide. The first wavelength range, the second wavelength range, and / or the third wavelength range may be, for example, up to about 2000 nm, 1000 nm, 700 nm, 500 nm, 400 nm, 300 nm, or 250 nm wide. In some embodiments, each of the first ORU 39 and the second ORU 49 has a RW outside each thickness range in the first wavelength range d1, the second wavelength range d2, and the third wavelength range d3.In some embodiments, the optical film 300 does not include a group of at least 8, 10, 12, 15, 20, 30, 40, 50, 60, 70, 80, 90, or 100 sequentially numbered ORUs, wherein each ORU in the group has a range of wavelengths (RW) within a second wavelength range (e.g., d2), and wherein the group does not overlap with the second group. In some embodiments, the ORUs in the second group are sequentially numbered among the sequentially numbered ORUs. In some embodiments, the ORUs in the second group are consecutive to each other.

[0084] In some embodiments, the optical film includes a plurality of optical repeating units (ORUs) 10, wherein the ORUs in the plurality of ORUs 10 are sequentially numbered from the same first main side 301 of the optical film 300 to the opposite second main side 302 of the optical film 300. In some embodiments, a scatter plot 20 of the ORU thickness versus numbering includes at least three non-overlapping first groups of ORUs (e.g., 31 and 135; 32 and 136; and 33 and 137—see example). Figure 4B and Figure 5B Each group in the first group includes at least three ORUs from the plurality of sequentially numbered ORUs, including a first ORU and a second ORU having the corresponding maximum and minimum thicknesses among the at least three ORUs in that group (e.g., 36a and 37a; 36b and 37b; 36c and 37c—see example). Figure 4A and Figure 5A In some implementations, for each group in the first group, the minimum thickness and the maximum thickness in that group differ from each other by at least approximately 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 70% (see example...). Figure 4A , Figure 5A , Figure 9 The minimum and maximum thicknesses in each group may differ by, for example, up to about 600%, 500%, 400%, 300%, 250%, 200%, 150%, or 100%. In some embodiments, for each first ORU and second ORU in at least three non-overlapping groups of ORUs, the thickness of the ORU is within about 10%, 9%, 8%, 7%, 6%, 5%, or 4% of each other. Scatter plot 20 may also include at least one second group of ORU 10 (e.g., 34 or 134—see example). Figure 4B and Figure 5B ), where each second group does not overlap with each first group.

[0085] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, wherein each ORU has a peak reflectivity at a corresponding resonant wavelength (RW). In some embodiments, the RW of the ORUs versus the depth of the ORUs relative to the same principal side (e.g., 301) of the optical film 300 scatter plot 20 includes at least three non-overlapping first group ORUs (e.g., 31 and 135; 32 and 136; and 33 and 137—see example). Figure 4B and Figure 5B Each group in the first group includes at least three ORUs from the plurality of sequentially numbered ORUs, including the first ORU and the second ORU having the corresponding largest and smallest RW among the at least three ORUs in that group (e.g., 36a and 37a; 36b and 37b; 36c and 37c—see example). Figure 4A and Figure 5A In some implementations, for each group in the first group, the minimum RW and the maximum RW in that group differ from each other by at least 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, or 70% (see example...). Figure 4A , Figure 5A , Figure 6 The minimum and maximum RW in each group may differ by, for example, up to about 600%, 500%, 400%, 300%, 250%, 200%, 150%, or 100%. In some embodiments, for each first ORU and second ORU in at least three non-overlapping groups of ORUs, the RW of the ORUs is within about 10%, 8%, 6%, 5%, or 4% of each other. Scatter plot 20 may also include at least one second group of ORU 10 (e.g., 34 or 134—see example). Figure 4B and Figure 5B ), where each second group does not overlap with each first group.

[0086] Figures 13 to 14 This is a schematic diagram of the reflection depth relative to wavelength from the same main side of the optical film, according to some implementation schemes. Figure 13 It can correspond to, for example Figures 5A to 5B , Figure 6 or Figure 9 Optical films. For example. Figure 6 and Figure 9 The example modeled optical films have average reflection depths of approximately 12.4 μm, 88.9 μm, and 19.1 μm for corresponding wavelengths, such as 450 nm, 525 nm, and 615 nm. Figure 14 It can correspond to, for example Figure 3 or Figures 11A to 12BOptical films. For example. Figures 11A to 12B The example modeled optical films have average reflection depths of approximately 29.4 μm, 3.7 μm, and 48.9 μm for corresponding wavelengths, such as 450 nm, 525 nm, and 615 nm. This includes a fourth stack of ORUs for reflection in the green wavelength range (e.g., in addition to...). Figure 4B Examples of stacks other than 34a to 34c in the above examples, and with a smaller total number of ORUs (75 instead of 300), have average reflection depths of approximately 7.1 μm, 1.7 μm, and 11.5 μm for corresponding wavelengths of, for example, 450 nm, 525 nm, and 615 nm. For example, by stacking ORUs 10 that produce reflections in these ranges (see, for example...) Figure 3 Replace with, for example Figures 4A to 4B The schematic illustration of multiple stacks of each range allows for Figure 14 The reflection depths for wavelength ranges W1 to W2 and W5 to W6 are closer to each other. In some embodiments, W1 is about 300 nm, 320 nm, 340 nm, 360 nm, 380 nm, 400 nm, or 420 nm. In some embodiments, W6 is about 3000 nm, 2500 nm, 2000 nm, 1500 nm, 1200 nm, 1000 nm, 900 nm, 800 nm, 750 nm, 700 nm, 680 nm, or 670 nm. In some embodiments, W2 is about 470 nm or 480 nm. In some embodiments, W3 is about 490 nm or 500 nm. In some embodiments, W4 is about 550 nm, 560 nm, or 570 nm. In some embodiments, W5 is about 580 nm, 590 nm, or 600 nm. In some implementations, W7 is in the range of about 510 nm to about 540 nm, or about 520 nm to about 530 nm (e.g., W7 may be about 525 nm).

[0087] In some embodiments, the optical film 300 includes a macro layer 124 and a plurality of optical repeating units (ORUs) 10 disposed on the same first main surface 124a of the macro layer 124. The plurality of ORUs 10 are disposed on the same side of the macro layer 124 and may be disposed between the outermost first macro layer 124 and the second macro layer 126. In some embodiments, for incident light 100 incident on the optical film at a first incident angle θ and for at least a first polarization state (e.g., polarization states 101 and / or 102): the plurality of ORUs 10 have a first average reflection depth, a second average reflection depth, and a third average reflection depth F1 to F3 relative to the first main surface 124a of the macro layer 124 within corresponding non-overlapping first wavelength range, second wavelength range, and third wavelength range (e.g., W1 to W2, W3 to W4, and W5 to W6), wherein the second wavelength range is disposed between the first wavelength range and the third wavelength range. In some embodiments, the second average reflection depth F2 differs from each of the first and third average reflection depths by (e.g., difference V2, or each of |F2-F1| and |F2-F3|) at least about 1.2 times, 1.22 times, 1.24 times, 1.26 times, 1.28 times, 1.3 times, 1.35 times, 1.4 times, 1.5 times, 1.6 times, 1.7 times, 1.8 times, 1.9 times, 2 times, 2.25 times, 2.5 times, 2.75 times, 3 times, 3.5 times, 4 times, 5 times, 6 times, 7 times, 8 times, 9 times, or 10 times. In some embodiments, each of the first, second, and third wavelength ranges is at least about 20 nm, 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, or 60 nm wide. In some embodiments, each of the first, second, and third wavelength ranges is positioned between about 380 nm, 400 nm, or 420 nm and about 3000 nm, 2500 nm, 2000 nm, 1500 nm, 1200 nm, 900 nm, 88 nm, 700 nm, and 680 nm. For example, in some embodiments, each of the first, second, and third wavelength ranges is positioned between about 380 nm and about 2500 nm, or between about 400 nm and about 700 nm, or between about 420 nm and about 680 nm. In some embodiments, the first, second, and third wavelength ranges are corresponding blue, green, and red wavelength ranges. In some implementations, the blue wavelength range extends from about 420 nm to about 480 nm, the green wavelength range extends from about 490 nm to about 560 nm, and the red wavelength range extends from about 590 nm to about 670 nm.In some embodiments, for incident light 100 incident on the optical film at a first incident angle θ and for at least a first polarization state (e.g., polarization state 101 and / or 102), the optical film has an average reflectivity of at least about 60%, 70%, 80%, 85%, 90%, or 95% in each of the first, second, and third wavelength ranges.

[0088] In some embodiments, the second average reflection depth F2 is less than about 10 micrometers, 9 micrometers, 8 micrometers, 7.5 micrometers, 7 micrometers, 6.5 micrometers, 6 micrometers, 5.5 micrometers, 5 micrometers, 4.5 micrometers, 4 micrometers, 3.5 micrometers, 3 micrometers, 2.5 micrometers, or 2 micrometers. In some embodiments, the first average reflection depth F1 and the third average reflection depth F3 are within about 23 micrometers, 22.5 micrometers, 22 micrometers, 21.5 micrometers, 21 micrometers, 20.5 micrometers, 20 micrometers, 19.5 micrometers, 19 micrometers, 17 micrometers, 15 micrometers, 12 micrometers, 10 micrometers, 9 micrometers, 8 micrometers, 7 micrometers, 6 micrometers, or 5 micrometers of each other. In some such embodiments, or in others, the second average reflection depth F2 differs from each of the first average reflection depth F1 and the third average reflection depth F3 by a factor greater than about 23 micrometers, 23.5 micrometers, 24 micrometers, 24.5 micrometers, 25 micrometers, 25.5 micrometers, 26 micrometers, 30 micrometers, 35 micrometers, 40 micrometers, 45 micrometers, 50 micrometers, 55 micrometers, or 60 micrometers. For example, in some embodiments, the first average reflection depth F1 and the third average reflection depth F3 are within about 21.5 micrometers of each other, and the second average reflection depth F2 differs from each of the first average reflection depth F1 and the third average reflection depth F3 by a factor greater than about 24.5 micrometers. As another example, in some embodiments, the first average reflection depth F1 and the third average reflection depth F3 are within about 8 micrometers of each other, and the second average reflection depth F2 differs from each of the first average reflection depth F1 and the third average reflection depth F3 by a factor greater than about 40 micrometers. In some embodiments, each of F1, F2, and F3 is in the range of about 5% to about 95% or about 10% to about 90% of the total average thickness of the plurality of optical repeating units 10.

[0089] In some implementations, as further described elsewhere herein, the plurality of ORUs 10 includes at least three first ORUs (e.g., x1 to x3, y1 to y3, or z1 to z3—see example) having a thickness within P1% of the same first thickness (e.g., a1, a2, or a). Figure 4A and Figure 5AEach first ORU is separated from each other first ORU by at least one ORU having a thickness that differs from the first thickness by more than P1%, wherein P1% is in the range of about 1% to about 10% or another range described elsewhere herein.

[0090] In some embodiments, the first angle of incidence θ is less than about 30 degrees, 25 degrees, 20 degrees, 15 degrees, 10 degrees, or 5 degrees. In some embodiments, the first angle of incidence θ is greater than about 5 degrees, 10 degrees, 15 degrees, 20 degrees, 25 degrees, or 30 degrees. In some such embodiments, or in other embodiments, the first angle of incidence θ is less than about 75 degrees, 70 degrees, 65 degrees, 60 degrees, 55 degrees, 50 degrees, 45 degrees, 40 degrees, 35 degrees, or 30 degrees. The first angle of incidence θ may be, for example, between about 5 degrees and about 75 degrees, or between about 10 degrees and about 70 degrees, or between about 30 degrees and about 60 degrees.

[0091] In some embodiments, each ORU in ORU 10 has a peak reflectivity at the corresponding resonant wavelength (RW), and for incident light 100 incident on optical film 300 at a first incident angle θ and for at least a first polarization state, and for a first wavelength within one of a first wavelength range and a third wavelength range (e.g., a1 or a1—see example...). Figure 4A and Figure 5A The optical film 300 includes at least three first ORUs (e.g., x1 to x3 or y1 to y3) having a RW within 20%, 15%, 12%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, or 1% of the first wavelength. In some embodiments, the first ORUs are spaced apart from each other by at least about 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.25 μm, 1.5 μm, 1.75 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 12 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm along the thickness direction (z-direction) of the optical film 300. For example, the first ORUs may be x1 to x3, which may have corresponding depths b1 to b3 (see example...). Figure 4A or Figure 5AFurthermore, each of b2-b1 and b3-b2 may be at least about 0.5 micrometers or another range of these ranges. In some embodiments, the first ORUs are spaced apart from each other along the thickness direction of the optical film 300 by no more than about 150 micrometers, 100 micrometers, 50 micrometers, 30 micrometers, 20 micrometers, 15 micrometers, or 10 micrometers. For example, each of b2-b1 and b3-b2 may be in the range of about 0.5 micrometers to about 100 micrometers or about 1 micrometer to about 50 micrometers. In some embodiments, for incident light 100 incident on the optical film 300 at a first incident angle θ and for at least a first polarization state, and for a second wavelength in another wavelength range of the first and third wavelength ranges, the optical film includes at least three second ORUs having a relative wavelength (RW) within 20%, 15%, 12%, 10%, 9%, 8%, 7%, 6%, 5%, 4%, 3.5%, 3%, 2.5%, 2%, 1.5%, or 1% of the second wavelength. In some embodiments, the second ORUs are spaced apart from each other by at least about 0.5 μm, 0.6 μm, 0.7 μm, 0.8 μm, 0.9 μm, 1 μm, 1.25 μm, 1.5 μm, 1.75 μm, 2 μm, 2.5 μm, 3 μm, 4 μm, 5 μm, 6 μm, 7 μm, 8 μm, 9 μm, 10 μm, 12 μm, 14 μm, 15 μm, 16 μm, 17 μm, 18 μm, 19 μm, or 20 μm along the thickness direction of the optical film. For example, the second ORUs can be y1 to y3, which can have corresponding depths c1 to c3 (see example...). Figure 4A or Figure 5A Furthermore, each of c2-c1 and c3-c2 may be at least about 0.5 micrometers or another range thereof. In some embodiments, the second ORUs are spaced apart from each other along the thickness direction of the optical film 300 by no more than about 150 micrometers, 100 micrometers, 50 micrometers, 30 micrometers, 20 micrometers, 15 micrometers, or 10 micrometers. For example, each of c2-c1 and c3-c2 may be in the range of about 0.5 micrometers to about 100 micrometers or about 1 micrometer to about 50 micrometers.

[0092] In some embodiments, the optical film 300 includes a macro layer 124 and a plurality of optical repeating units (ORUs) 10 disposed on the same first main surface 124a of the macro layer 124. In some embodiments, when adjacent data points in a scatter plot 20 of ORU thickness pair numbering are connected by straight line segments to form a continuous line plot, the continuous line plot includes a plurality of first lines 24 that alternate and intersect with a plurality of second lines 25, in which the ORU thickness in all first lines substantially increases as the ORU number increases or decreases, and in which the ORU thickness in all second lines substantially decreases as the ORU number increases or decreases, such that for incident light 100 incident on the optical film 300 at a first incident angle θ and for at least one polarization state (e.g., 101 and / or 102): for a first wavelength (e.g., a, a1, or a2, see example) in the visible wavelength range extending from about 420 nm to about 680 nm. Figure 4A and Figure 5A The reflection depth (e.g., F2) of the plurality of ORUs 10 relative to the first primary surface 124a of the macroscopic layer 124 is less than about 10 micrometers, 9 micrometers, 8 micrometers, 7.5 micrometers, 7 micrometers, 6.5 micrometers, 6 micrometers, 5.5 micrometers, 5 micrometers, 4.5 micrometers, or 4 micrometers. The reflection depth may be, for example, at least about 0.25 micrometers, 0.5 micrometers, 1 micrometer, or 1.5 micrometers. In some embodiments, for incident light 100 incident on the optical film 300 at a first incident angle θ and for at least one polarization state, for a wavelength range at least 20 nm, 25, 30 nm, 35, 40 nm, 45, 50 nm, 55, or 60 nm wide and substantially centered on a first wavelength (e.g., W7) (e.g., W3 to W4—see example...), Figures 13 to 14 The plurality of ORUs 10 have an average reflectivity greater than about 60%, 70%, 80%, 85%, 90%, or 95%. The wavelength range can be, for example, a green wavelength range extending from about 490 nm to about 560 nm. In some embodiments, the first wavelength is in the wavelength range extending from about 490 nm to about 560 nm. In some embodiments, for incident light 100 incident on the optical film 300 at a first incident angle θ and for at least one polarization state, in the visible wavelength range, the reflection depth of the optical film 300 from the same first principal side 301 of the optical film 300 varies rather than monotonically with increasing wavelength of the incident light 100.

[0093] In some embodiments, the optical film 300 includes a macro layer 124 and a plurality of optical repeating units (ORUs) 10 disposed on the same first main surface 124a of the macro layer 124, wherein each ORU in the ORU 10 has a peak reflectivity at the corresponding resonant wavelength (RW).

[0094] In some implementations, when adjacent data points in a scatter plot 20 of the RW of the ORU relative to the depth of the ORU relative to the first master surface 124a of the macro layer 124 are connected by straight line segments to form a continuous line plot, the continuous line plot may include a plurality of first lines 24 that alternate and intersect with a plurality of second lines 25, wherein the ORU RW in all the first lines substantially increases with the same condition of increasing or decreasing ORU depth, and the ORU RW in all the second lines substantially decreases with the same condition of increasing or decreasing ORU depth (see, for example...). Figure 3 , Figure 4A , Figure 5A , Figure 6 , Figure 11B In some embodiments, the optical film 300 is configured such that, for incident light 100 incident on the optical film 300 at a first incident angle θ and for at least one polarization state (e.g., 101 and / or 102): for a first wavelength (e.g., a, a1, a2, or W7) in a visible wavelength range extending from about 420 nm to about 680 nm, the plurality of ORUs have a reflection depth relative to the first master surface of the macroscopic layer of less than about 10 micrometers (or within the range described elsewhere herein); and for a wavelength range at least 20 nm wide and substantially centered on the first wavelength, the plurality of ORUs have an average reflectivity greater than about 60%. In some embodiments, the wavelength range is at least 25 nm, 30 nm, 35 nm, 40 nm, 45 nm, 50 nm, 55 nm, or 60 nm wide. The wavelength range may be a green wavelength range as further described elsewhere herein. In some embodiments, the first wavelength is in a (e.g., green) wavelength range extending from about 490 nm to about 560 nm. In some embodiments, the plurality of ORUs 10 have an average reflectivity greater than about 60%, 70%, 80%, 85%, 90%, or 95% in the wavelength range. In some embodiments, for incident light 100 incident on the optical film 300 at a first incident angle θ and for at least one polarization state, in the visible wavelength range, the reflection depth of the optical film 300 from the same first principal side 301 of the optical film 300 varies rather than monotonically with increasing wavelength of the incident light.

[0095] Figure 15This is a schematic illustration of reflection from optical film 300 according to some implementation schemes. In some embodiments, the optical film 300 includes a plurality of polymer layers (e.g., layer A and layer B) stacked along the thickness direction (z-direction) of the optical film 300 such that when a substantially monochromatic first ray 110a having a first wavelength and optical intensity Ii1 is incident on the plurality of polymer layers at a first incident angle θ greater than about 5 degrees (or within the range described elsewhere herein), and a substantially monochromatic second ray 111 having a second wavelength different from the first wavelength and optical intensity Ii2 ≤ Ii1 is incident on the plurality of polymer layers at the first incident angle θ, the plurality of polymer layers reflect the incident first ray instead of the incident second ray as at least two spaced-apart first reflected rays 120a, 120b having corresponding at least two first optical intensities Ira, Irb, each of the at least two first optical intensities being greater than about 0.1 Ii1, and the plurality of polymer layers reflect the incident second ray as a second reflected ray having a second optical intensity greater than about 0.5 Ii2, wherein the second optical intensity is greater than each of the at least two first optical intensities. In some embodiments, each of the at least two first optical intensities is greater than about 0.15, 0.2, 0.25, 0.3, 0.35, or 0.4 times that of Ii1. In some such embodiments, or in others, the second optical intensity is greater than about 0.55, 0.6, 0.65, 0.7, 0.75, 0.8, 0.85, 0.9, 0.92, 0.94, 0.95, 0.96, or 0.97 times that of Ii2. In some such embodiments, or in others, at least one of the at least two first optical intensities is less than about 0.9, 0.85, 0.8, 0.75, 0.7, 0.65, 0.6, 0.55, 0.5, or 0.45 times that of Ii1.

[0096] In some embodiments, the difference S2 between at least two adjacent reflected rays of the at least two spaced-apart first reflected rays is greater than the average total thickness S1 of at least 4, 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20, 25, 30, 35, 40, 50, 60, 70, 80, 90, or 100 sequentially stacked polymer layers. In some embodiments, the polymer layers in the plurality of polymer layers have a total thickness S4, and the maximum difference S3 between the first and second reflected rays is less than about 2S4 or less than about 1.9 times, 1.8 times, 1.7 times, 1.6 times, 1.5 times, or 1.4 times S4. The wavelength distribution of essentially monochromatic light can be small enough (e.g., less than the full width at half maximum of about 15 nm, 10 nm, or 5 nm) that the difference between the difference S2 and the interval produced by monochromatic light without wavelength distribution is negligible (e.g., less than about 15%, 10%, or 5%). Suitable essentially monochromatic light sources include, for example, lasers and laser diodes.

[0097] Figure 16 This is a schematic diagram of the reflectivity versus wavelength of an optical repeating unit 10 according to some embodiments. The resonant wavelength (RW) of an optical repeating unit (ORU) can be defined as the wavelength at which the ORU exhibits peak reflectivity. Peak reflectivity, and therefore the resonant wavelength, can vary with the angle of incidence and polarization. For example, for perpendicularly incident light, the resonant wavelength is typically twice the optical thickness of the ORU, while at an oblique angle, the resonant wavelength is typically smaller than that for perpendicularly incident light, and furthermore, the resonant wavelength is typically different for s-polarized and p-polarized light. Figure 16 In this context, the ORU has a peak reflectivity at the corresponding resonant wavelength RW. As is known in the art, stacking ORU 10 can generate reflectivity bands by overlapping the reflectivity of the ORU 10 in the stack.

[0098] Figures 17 to 18 This is a schematic diagram of the reflectivity of an optical film and a non-overlapping group of ORUs of the optical film relative to wavelength according to some embodiments. The result of s-polarization state 102 at an incident angle θ of 45 degrees is shown, wherein light 100 is incident from a glass having a refractive index of about 1.8 for at least one wavelength in the visible wavelength range of about 420 nm to about 680 nm. Figure 17 It uses standard optical modeling techniques from Figure 9The ORU thickness distribution was calculated, where birefringent LmPEN was used for layer A and optically isotropic coPEN was used for layer B. Rs-1 refers to the reflectance from combination groups 90 and 90', Rs-2 refers to the reflectance from combination groups 91 and 91', Rs-3 refers to the reflectance from combination groups 92 and 92', Rs-4 refers to the reflectance from combination groups 93 and 93', Rs-5 refers to the reflectance from group 94, and Rs-All refers to the reflectance from optical film 300. Figure 18 It uses standard optical modeling techniques from Figures 12A to 12B The ORU thickness distribution was calculated, where birefringent LmPEN was used for layer A and optically isotropic coPEN was used for layer B. Rs-1 refers to the reflectance from group 90, Rs-2 refers to the reflectance from group 91, Rs-3 refers to the reflectance from group 92, Rs-4 refers to the reflectance from group 93, Rs-5 refers to the reflectance from combined groups 94 and 94', and Rs-All refers to the reflectance from optical film 300.

[0099] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, wherein the ORUs in the plurality of ORUs 10 are sequentially numbered from the same first main side 301 of the optical film 300 to the opposite second main side 302 of the optical film 300, such that the average thickness of the sequentially numbered ORUs in the plurality of ORUs 10 relative to the numbering scatter plot 20 includes at least three non-overlapping groups of ORUs (e.g., 34a to 34c, or combined groups 31, 135; 32, 136; and 33, 137—see example). Figure 3 , Figure 4B and Figure 5BEach group within the groups comprises at least two ORUs from the sequentially numbered ORUs in the plurality of ORUs 10, and for each pair of adjacent first and second groups in the at least three groups, the first group (e.g., 34a or combination groups 31, 135) comprises the first ORU (e.g., 36d or 36a) closest to the second group (e.g., 34b or combination groups 32, 136), and the second group comprises the second ORU (e.g., 37e or 37b) closest to the first group. In some embodiments, the average thickness of the first ORU and the second ORU differs by at least about 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%. The average thickness of the first ORU and the second ORU may differ by, for example, up to about 600%, 500%, 400%, 300%, 250%, 200%, 150%, or 100%. In some embodiments, each of at least two of the at least three non-overlapping groups of ORUs includes at least three sequentially numbered ORUs from the plurality of ORUs 10. In some embodiments, each of the at least three non-overlapping groups of ORUs includes at least three sequentially numbered ORUs from the plurality of ORUs 10. In some embodiments, at least one of the at least three non-overlapping groups of ORUs includes at least four, five, or six sequentially numbered ORUs from the plurality of ORUs 10. In some embodiments, each of the at least three non-overlapping groups of ORUs includes no more than 200, 150, 120, 100, 80, 60, 40, or 20 sequentially numbered ORUs from the plurality of ORUs 10. In some embodiments, the at least three non-overlapping groups of ORUs include no more than 20, 15, 12, 10, 9, 8, 7, 6, 5, or 4 non-overlapping groups of ORUs. In some implementations, at least three non-overlapping groups of the ORU include at least four non-overlapping groups of ORU 10.

[0100] In some embodiments, for incident light 100 incident on optical film 300 at a first incident angle θ and for at least one polarization state (e.g., 101 and / or 102), and for at least a first wavelength (e.g., Wa—see example) in the visible wavelength range extending from about 420 nm to about 680 nm. Figures 17 to 18The plurality of ORUs 10 and at least one group of at least three non-overlapping groups have corresponding optical reflectivities R and R1, wherein R > R1 > 10%, and R / R1 ≥ 1.1, 1.15, 1.2, 1.3, 1.4, 1.5, 1.75, 2, 2.5, 3, 4, 5, 6, 7, 8, 9, or 9.5. In some embodiments, R > R1 > 15%, 20%, 25%, 30%, 35%, 40%, 45%, or 50%. In some embodiments, for incident light 100 incident on the optical film 300 at a first incident angle θ and for at least one polarization state, and for at least a second wavelength in the visible wavelength range different from the first wavelength (e.g., Wb—see example) Figures 17 to 18 The plurality of ORUs 10 and groups of at least three, five, ten, twenty, thirty, forty, fifty, sixty, or seventy sequentially numbered ORUs that do not overlap with any of the at least three non-overlapping groups of ORUs have corresponding optical reflectivities R' and R1', wherein R1' ≥ 50%, 60%, 70%, 80%, 85%, 90%, 92%, 94%, 95%, 96%, or 97% and 1.25 > R' / R1'. In some embodiments, R' / R1' is less than 1.2, 1.15, 1.1, or 1.05. In some embodiments, R' ≥ R1'. In some embodiments, R' and R1' are substantially equal (e.g., equal within about 5%, 4%, 3%, 2%, or 1%). In some embodiments, for incident light 100 incident on optical film 300 at a first incident angle θ and for at least one polarization state, the reflection depth of optical film from the same first principal side 301 of optical film 300 varies rather than monotonically with increasing wavelength of incident light 100 in the visible wavelength range.

[0101] In some embodiments, the optical film 300 includes a plurality of optical repeating units (ORUs) 10, which are sequentially numbered from the same first principal side 301 of the optical film 300 to the opposite second principal side 302 of the optical film 300, wherein each ORU has a peak reflectivity at a corresponding resonant wavelength (RW), such that a scatter plot 20 of RW versus depth of the ORU relative to the first principal side 301 of the optical film 300 includes at least three non-overlapping groups of ORUs (e.g., 34a to 34c, or combined groups 31, 135; 32, 136; and 33, 137—see example). Figure 3 , Figure 4B and Figure 5BEach group within the plurality of ORUs comprises at least two sequentially numbered ORUs, and for each pair of adjacent first and second groups in the at least three groups, the first group (e.g., 34a or combination groups 31, 35) comprises the first ORU (e.g., 36d or 36a) closest to the second group (e.g., 34b or combination groups 32, 36), and the second group comprises the second ORU (e.g., 37e or 37b) closest to the first group. In some embodiments, the RW of the first and second ORUs differs by at least about 5%, 6%, 7%, 8%, 9%, 10%, 15%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90%, or 100%. In some embodiments, each of at least two of the at least three non-overlapping groups of ORUs comprises at least three sequentially numbered ORUs in the plurality of ORUs 10. The number of ORUs in at least three non-overlapping groups and / or the number of ORUs in at least three non-overlapping groups may be within any range described elsewhere herein. These multiple ORUs 10 and each ORU group are for a first wavelength and a second wavelength (e.g., Wa and Wb—see example). Figures 17 to 18 The optical reflectivity (e.g., R, R1, R', and R1') of the α can be within any of the corresponding ranges described elsewhere in this document.

[0102] Figure 19This is a schematic cross-sectional view of an optical system 400 according to some embodiments. The optical system 400 may include an optical film 300 for reducing chromatic aberration. For example, the optical film 300 may be a reflective polarizer, and including an optical film instead of a conventional reflective polarizer can reduce the amplitude of the chromatic aberration of the optical system 400 by at least about 5%, 10%, 15%, or 20% compared to using a conventional reflective polarizer. In some embodiments, for incident light at a first incident angle and for a first polarization state (e.g., polarization state 101, which may be a blocking polarization state for each of the optical film 300 and the conventional reflective polarizer): within a predetermined wavelength range, the reflection depth of the optical film 300 from the same first principal side of the optical film 300 varies rather than monotonically with increasing wavelength of the incident light, whereas, within a predetermined wavelength range, the reflection depth of a comparative reflective polarizer from the same principal side of the optical film 300 varies monotonically with increasing wavelength of the incident light. An example conventional reflective polarizer is an APF purchased from 3M Company, St. Paul, MN. Chromatic aberration is an optical aberration in which the lateral and / or longitudinal focus of light varies with wavelength, as exemplified by, for example, U.S. Patent Application Publication No. 2020 / 0341267 (Wong). Chromatic aberration can be a longitudinal (also called axial) aberration defined along the optical axis 290 of the optical system 400.

[0103] In some embodiments, the optical system 400 includes: a display 200 configured to form and emit an image 201; at least one optical component 220, 221, wherein the at least one optical component has dispersion; and any one of the optical films 300 of this specification, which is in optical communication with the display 200 and each of the at least one optical component 220, 221. In some embodiments, the optical film 300 (e.g., via a wavelength having a desired depth of reflection) is configured to at least partially compensate for the dispersion of the at least one optical component 220, 221. The term "optical communication," as applied to two objects or components, means that light can be transmitted directly or indirectly from one object to another using optical methods (e.g., direct transmission, reflection, diffraction, or refraction). The display 200 may be, for example, a liquid crystal display or an organic light-emitting diode display. Optical system 400 may be a foldable optical system, such as those substantially described in, for example, U.S. Patent No. 10,678,052 (Ouderkirk et al.); U.S. Patent No. 11,156,814 (Steiner et al.); and U.S. Patent No. 11,630,290 (Yun et al.). In some embodiments, optical system 400 has an optical axis 290 such that light rays 291 propagating along the optical axis 290 pass through the at least one optical component 220, 221 and optical film 300 (e.g., in a foldable optical system, light rays may be transmitted through optical film 300 after being first reflected by it) without being substantially refracted.

[0104] In some embodiments, the optical system 400 includes a display 200 configured to form and emit an image 201, the image including overlapping first emitted image rays 203a and second emitted image rays 203b, the first and second emitted image rays having corresponding first and second wavelengths separated by at least about 20 nm, 30 nm, 40 nm, 50 nm, or 60 nm. In some embodiments, the first and second wavelengths are in the visible wavelength range extending from about 420 nm to about 680 nm. In some embodiments, the first wavelength is a blue or red wavelength, and the second wavelength is a green wavelength. The optical system 400 may be configured to display a virtual image 202 of the emitted image 201 to an observer 210. The optical system 400 includes: at least one optical component 220, 221, wherein the at least one optical component has dispersion; and an optical film 300 comprising a plurality of polymer layers (e.g., layer A and layer B) and configured to at least partially compensate for the dispersion of the at least one optical component. Each of the plurality of polymer layers may have an average thickness of less than about 500 nm (or within the range described elsewhere herein). In some embodiments, for incident light 100 incident on optical film 300 at a first incident angle θ and for at least one polarization state (e.g., at least one of 101 and 102), the depth of reflection of optical film 300 from the same first principal side surface (e.g., 301) of optical film 300 varies rather than monotonically with increasing wavelength of incident light 100 within a predetermined wavelength range including a first wavelength and a second wavelength. In some embodiments, the predetermined wavelength range is, for example, from about 420 nm to about 680 nm. In some embodiments, the optical system 400 causes the optical interaction (e.g., refraction caused by a material exhibiting dispersion) between the at least one optical component 220, 221 and the coincident first emitted image ray 203a and second emitted image ray 203b to laterally separate the first emitted image ray and the second emitted image ray (the coincident first emitted image ray 203a and second emitted image ray 203b become laterally separated first emitted image ray 204a and second emitted image ray 204b), such that when incident on the optical film 300, the first emitted image ray 204a and second emitted image ray 204b are separated by a first distance G1, and the plurality of polymer layers reflect the incident first emitted image ray and second emitted image ray into corresponding reflected first image ray 205a and second image ray 205b separated by a second distance G2, wherein G2 is at least 10% smaller than G1 ([G1-G2] / G1 multiplied by 100% equals at least 10%). In some embodiments, G2 is at least 20% or at least 50% smaller than G1. In some implementations, G1 is at least 2, 2.5, 3, 5, 7, 10, 20, 50, or 100 times G2.

[0105] In some embodiments, the first emitted image ray 203a and the second emitted image ray 203b have corresponding optical intensities I1 and I2, and the reflected first image ray 205a and the second image ray 205b have corresponding optical intensities Q1 and Q2. In some embodiments, each of Q1 / I1 and Q2 / I2 is greater than about 0.15, 0.2, 0.3, or 0.4.

[0106] In some embodiments, the at least one optical component 220, 221 includes a metasurface. In some embodiments, the at least one optical component 220, 221 includes a diffractive surface. For example, surface 222 of optical component 221 may be a metasurface and / or a diffractive surface. In some embodiments, the at least one optical component includes a refractive optical lens (e.g., 220 and / or 221 may be or include a refractive optical lens). In some embodiments, the at least one optical component includes at least two optical lenses (e.g., 220 and 221). In some embodiments, the at least one optical component is or includes a multilayer optical film. For example, element 221 or 240 may be a multilayer optical film with a generally similar appearance. Figure 1 The diagram is illustrated schematically. Element 240 may be, for example, a partial reflector, which may be a multilayer optical film.

[0107] In some embodiments, the optical film 300 is or includes a reflective polarizer such that, for substantially perpendicular incident light, the reflective polarizer reflects at least 60% of the incident light polarized along a first in-plane direction and transmits at least 60% of the incident light polarized along an orthogonal second in-plane direction. In some embodiments, for substantially perpendicular incident light in the visible wavelength range of about 420 nm to about 680 nm, the reflective polarizer has an average reflectivity greater than about 60%, 70%, 80%, or 90% for a first polarization state 101 and an average transmittance greater than about 60%, 70%, 80%, or 85% for an orthogonal second polarization state 102.

[0108] In some embodiments, the optical system 400 further includes a partial reflector 240 such that, for substantially perpendicular incident light and for each of the mutually orthogonal polarization states 101 and 102, the partial reflector reflects at least 30% of the incident light and transmits at least 30% of the incident light. In some embodiments, for substantially perpendicular incident light and for each of the mutually orthogonal polarization states 101 and 102, the partial reflector reflects at least 40% of the incident light and transmits at least 40% of the incident light. The partial reflector 240 may be, for example, a half-silvered mirror, or may be, for example, a multilayer optical film.

[0109] In some embodiments, the optical system 400 further includes a retardation layer 250. In some embodiments, the retardation layer 250 is disposed between the optical film 300 and the partial reflector 240. In some embodiments, the retardation layer 250 is configured to change the phase of vertically incident light having a first wavelength or a second wavelength by at least 20 degrees. In some embodiments, the retardation layer 250 is a quarter-wavelength retarder for at least one wavelength in the visible wavelength range including both the first and second wavelengths. The retardation layer 250 may be a single layer (e.g., a birefringent film layer) or may include multiple layers (e.g., a multilayer achromatic retarder).

[0110] In some embodiments, the optical system 400 further includes an absorptive polarizer 260. In some embodiments, the absorptive polarizer 260 absorbs at least 60% of the incident light polarized along a first in-plane direction and transmits at least 60% of the incident light polarized along an orthogonal second in-plane direction for substantially perpendicular incident light. In some embodiments, the absorptive polarizer absorbs at least 70% or 80% of the incident light polarized along a first in-plane direction and transmits at least 70% or 80% of the incident light polarized along a second in-plane direction for substantially perpendicular incident light. In some embodiments, the absorptive polarizer 260 is disposed between the optical film 300 and the observer 210. The absorptive polarizer 260 may include, for example, an iodine-stained polyvinyl alcohol layer. The first in-plane directions of the absorptive polarizer and the reflective polarizer may be the same direction, or they may be aligned within, for example, about 20 degrees, 15 degrees, 10 degrees, or 5 degrees.

[0111] Terms such as “about” will be understood in the context in which they are used and described in this specification by those skilled in the art. If the use of “about” to express quantities of characteristic size, quantity, and physical properties is unclear to those skilled in the art in the context in which it is used and described in this specification, then “about” will be understood to mean within 10% of the specified value. A quantity given a specified value as “about” can be precisely the specified value. For example, if it is unclear to those skilled in the art in the context in which it is used and described in this specification, a quantity having a value of about 1 means that the quantity has a value between 0.9 and 1.1, and that the value can be 1.

[0112] The term “substantially” will be understood by those skilled in the art in the context of its use and description in this specification. If, in the context of its use and description in this specification, the use of “substantially” regarding a property or characteristic is not readily apparent to those skilled in the art, and when the opposite meaning of such property or characteristic is clear to those skilled in the art, the term “substantially” will be understood to mean that the property or characteristic is more pronounced than its opposite meaning.

[0113] All cited references, patents, and patent applications are incorporated herein by reference in their entirety in a consistent manner. In the event of any inconsistency or contradiction between the incorporated references and this application, the information in the foregoing description shall prevail.

[0114] Unless otherwise indicated, the description of elements in the accompanying drawings should be understood to apply equally to corresponding elements in the other drawings. While specific embodiments have been illustrated and described herein, those skilled in the art will recognize that various alternative and / or equivalent embodiments may be used instead of the illustrated and described embodiments without departing from the scope of this disclosure. This application is intended to cover any modifications, variations, or combinations of the specific embodiments discussed herein. Therefore, this disclosure is intended to be limited only by the claims and their equivalents.

Claims

1. An optical film comprising a plurality of optical repeating units (ORUs), the plurality of ORUs being co-extruded and co-stretched together and totaling at least 10, each ORU having an average thickness of less than about 1500 nm and comprising at least a polymer A layer and different polymer B layers. The plurality of ORUs includes at least three first ORUs, each first ORU having a thickness within P1% of the same first thickness, each first ORU being separated from each other first ORU by at least one ORU having a thickness greater than P1% of the first thickness, P1% being in the range of about 1% to about 10%, and For incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range, the reflection depth of the optical film from the same first principal side surface of the optical film varies rather than monotonically with increasing wavelength of the incident light.

2. The optical film according to claim 1, wherein the plurality of ORUs includes at least three second ORUs, each second ORU having a thickness within P1% of the same second thickness, each second ORU being separated from each other second ORU by at least one ORU having a thickness greater than P1% of the second thickness, the second thickness differing from the first thickness by at least 10 nm.

3. The optical film according to claim 2, wherein the second thickness differs from the first thickness by at least about 1.5 times P1%.

4. The optical film according to claim 1, wherein the thickness of each ORU in the at least one ORU differs from the first thickness by more than P1%+0.5%, where P1% is in the range of about 1% to about 3%.

5. The optical film according to claim 1, wherein for the incident light incident on the optical film at the first incident angle and for the at least one polarization state: The plurality of ORUs have a first average reflection depth, a second average reflection depth, and a third average reflection depth relative to the same first main side surface of the optical film within corresponding non-overlapping first, second, and third wavelength ranges, the second wavelength range being disposed between the first and third wavelength ranges, and the second average reflection depth differing from each of the first and third average reflection depths by at least approximately 1.2 times the difference between the first and third average reflection depths.

6. The optical film of claim 1, wherein the plurality of ORUs are disposed on the same first main surface of a macroscopic layer having an average thickness greater than about 500 nm, wherein for the incident light incident on the optical film at the first incident angle and for the at least one polarization state: For a first wavelength within the predetermined wavelength range, the reflection depth of the plurality of ORUs relative to the first main surface of the macroscopic layer is less than about 10 micrometers.

7. An optical film comprising a macro layer and a plurality of optical repeating units (ORUs) totaling at least 10, the plurality of ORUs being disposed on the same first main surface of the macro layer, the macro layer and the plurality of optical repeating units being co-extruded and co-stretched with each other, the macro layer having an average thickness greater than about 500 nm, each ORU having an average thickness less than about 1500 nm and comprising at least a polymer A layer and different polymer B layers; Wherein, for incident light incident on the optical film at a first incident angle and for at least a first polarization state: The plurality of ORUs have a first average reflection depth, a second average reflection depth, and a third average reflection depth relative to the first main surface of the macroscopic layer within corresponding non-overlapping first, second, and third wavelength ranges. The second wavelength range is disposed between the first and third wavelength ranges. The second average reflection depth differs from each of the first and third average reflection depths by at least approximately 1.2 times the difference between the first and third average reflection depths. Each of the first, second, and third wavelength ranges is at least approximately 20 nm wide and is disposed between approximately 380 nm and approximately 2000 nm. The optical film has an average reflectivity of at least about 60% in each of the first, second, and third wavelength ranges.

8. The optical film according to claim 7, wherein the second average reflection depth is less than about 10 micrometers.

9. The optical film of claim 7, wherein each of the ORUs has a peak reflectivity at a corresponding resonant wavelength (RW), and wherein for incident light incident on the optical film at the first incident angle, for at least the first polarization state, and for a first wavelength within one of the first wavelength range and the third wavelength range, the optical film comprises at least three first ORUs having an RW within 20% of the first wavelength, the first ORUs being spaced apart from each other by at least about 0.5 micrometers along the thickness direction of the optical film.

10. An optical film comprising a plurality of optical repeating units (ORUs), the plurality of ORUs being co-extruded and co-stretched together and totaling at least 10, each ORU having an average thickness of less than about 1500 nm and comprising at least a polymer A layer and different polymer B layers, the ORUs being sequentially numbered from the same first principal side of the optical film to the opposite second principal side of the optical film. When adjacent data points in a scatter plot of the thickness versus number of the ORUs are connected by straight line segments to form a continuous line graph, the continuous line graph includes multiple first lines that alternate and intersect with multiple second lines. In the multiple first lines, the ORU thickness in all first lines substantially increases with the same condition of increasing and decreasing ORU number. In the multiple second lines, the ORU thickness in all second lines substantially decreases with the same condition of increasing and decreasing ORU number. The intersection points form multiple alternating peaks and valleys. The first first line of the multiple first lines includes multiple first straight line segments extending from the first valley of the multiple alternating peaks and valleys to the first peak of the multiple alternating peaks and valleys. The slope of the first straight line segment includes a minimum slope amplitude and a maximum slope amplitude. The minimum slope amplitude is at least about 0.5 nm per ORU number, and the maximum slope amplitude is at least about 3 times the minimum slope amplitude.

11. An optical film comprising a plurality of optical repeating units (ORUs), the plurality of ORUs being co-extruded and co-stretched together and totaling at least 10, each ORU having an average thickness of less than about 1500 nm and comprising at least a polymer A layer and different polymer B layers, the ORUs being sequentially numbered from the same first principal side of the optical film to the opposite second principal side of the optical film. Such that when adjacent data points in a scatter plot of ORU thickness pairs are connected by straight line segments to form a continuous line plot, the continuous line plot includes a plurality of first lines that alternate and intersect with a plurality of second lines. In the plurality of first lines, the ORU thickness in all first lines substantially increases with the same condition of increasing and decreasing ORU number. In the plurality of second lines, the ORU thickness in all second lines substantially decreases with the same condition of increasing and decreasing ORU number. The intersections form at least a first plurality of alternating peaks and valleys, wherein for each pair of adjacent peaks and valleys in the first plurality of alternating peaks and valleys, the difference in ORU thickness between the peak and the valley is greater than about 5 nm and less than about 120 nm.

12. The optical film of claim 1, wherein the intersection forms a second plurality of alternating peaks and valleys that do not overlap with the first plurality of alternating peaks and valleys.

13. An optical film comprising a plurality of polymer layers stacked along the thickness direction of the optical film, such that when a substantially monochromatic first ray having a first wavelength and an optical intensity Ii1 is incident on the plurality of polymer layers at a first incident angle greater than about 5 degrees and a substantially monochromatic second ray having a second wavelength different from the first wavelength and an optical intensity Ii2 ≤ Ii1 is incident on the plurality of polymer layers at the first incident angle, the plurality of polymer layers reflect the incident first ray without reflecting the incident second ray into at least two spaced-apart first reflected rays having corresponding at least two first optical intensities, wherein each of the at least two first optical intensities is greater than about 0.1 Ii1, and the plurality of polymer layers reflect the incident second ray into second reflected rays having a second optical intensity greater than about 0.5 Ii2, the second optical intensity being greater than each of the at least two first optical intensities.

14. An optical system, the optical system comprising: The display is configured to form and emit images; At least one optical component, said at least one optical component including dispersion; and The optical film according to any one of claims 1 to 13, wherein the optical film is in optical communication with each of the display and the at least one optical component, and the optical film is configured to at least partially compensate for the dispersion of the at least one optical component.

15. An optical system, the optical system comprising: A display configured to form and emit an image, the image comprising overlapping first and second emitted image rays having corresponding first and second wavelengths separated by at least about 20 nm, the optical system being configured to display a virtual image of the emitted image to an observer; At least one optical component, said at least one optical component including dispersion; and An optical film comprising a plurality of polymer layers and configured to at least partially compensate for the dispersion of the at least one optical component, each of the plurality of polymer layers having an average thickness of less than about 500 nm, wherein for incident light incident on the optical film at a first incident angle and for at least one polarization state, within a predetermined wavelength range including the first wavelength and the second wavelength, the reflection depth of the optical film from the same first principal side surface of the optical film varies rather than monotonically with increasing wavelength of the incident light; The optical interaction between the at least one optical component and the overlapping first and second emitted image rays laterally separates the first and second emitted image rays, such that when incident on the optical film, the first and second emitted image rays are separated by a first distance G1, and the plurality of polymer layers reflect the incident first and second emitted image rays into corresponding reflected first and second image rays separated by a second distance G2, where G2 is at least 10% smaller than G1.

Images