Hybrid diffuser and its manufacturing method

Abstract

To provide a hybrid diffuser which comprises a combination of a volume diffuser and a surface diffuser to maximize output uniformity.SOLUTION: A hybrid diffuser is disclosed, including a diffuser polymer having a planar side opposite a side with a surface profile and containing at least one optical material within the volume of and / or on the surface profile of the diffuser polymer. A method of manufacturing the hybrid diffuser is also disclosed. A system may include a light source and the hybrid diffuser. A method of using the system is also disclosed.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] FIELD OF THE INVENTION The present invention generally relates to a hybrid diffuser, which includes a diffuser material having a flat surface opposite a surface having a surface profile, and at least one optical material within the diffuser material and / or on the surface profile of the diffuser polymer. Methods for making the hybrid diffuser are disclosed. A system can include a light source and the hybrid diffuser. Methods for using the system are also disclosed. [Background technology]

[0002] Background of the Invention Diffusers are optical components that find use in a variety of applications to provide both homogenizing and beam shaping functions. Broad classifications of diffusers include surface diffusers and volume diffusers.

[0003] Surface-type diffusers rely on the surface relief profile of the interface between two media, such as glass or polymer and air, to scatter radiation through refraction at the interface between the two media. In particular, surface-type diffusers produce controlled scattering based on the precise height and size distribution of surface scattering centers, e.g., the surface profile. Surface-type diffusers are typically highly efficient at shaping light upon transmission. However, the resulting light and energy distribution from surface-type diffusers can be compromised by unwanted "ghosting," i.e., diffracted rays inherent to the surface profile of surface-type diffusers. In particular, surface-type diffusers may fail to provide a high degree of illumination uniformity. A well-known example of a surface-type diffuser is frosted glass, which is inexpensive and readily available on the market, but its beam-shaping capabilities are very limited.

[0004] On the other hand, volume diffusers are composed of particles embedded within a material matrix. Light scattering can be achieved by particles and / or voids (gas phase) distributed throughout the material matrix. Volume diffusers are generally less efficient at shaping light during transmission than surface diffusers. In fact, volume diffusers tend to produce intensity patterns that are highly inhomogeneous in terms of intensity distribution. A common example of a volume diffuser is opal glass, which can produce a Lambertian illumination pattern (which has an intensity profile described by a cosine function as a function of angle), but with very low efficiency, typically transmitting approximately 20% of the input light energy. Other volume diffusers that are less strong than opal glass tend to produce intensity profiles that exhibit Lorentzian intensity profiles. Also, unlike opal glass, these weaker volume diffusers can offer much higher efficiency. Summary of the Invention [Problem to be solved by the invention]

[0005] What is needed are items such as hybrid diffusers, such as volume diffusers combined with surface diffusers, to maximize output uniformity. For example, volume-related aspects of hybrid diffusers can enable the introduction of additional desired optical and non-optical functions. Furthermore, achieving layer-by-layer construction using precisely distributed layered nanoparticles / microparticles of different sizes and optical materials with different optical properties can provide opportunities to add other properties such as high refractive index optical media, anti-reflection, wavelength selectivity / dichroism, chemical and mechanical properties, etc. [Means for solving the problem]

[0006] In one embodiment, a hybrid diffuser is disclosed, the hybrid diffuser comprising a diffuser material having a flat surface opposite a surface having a surface profile, and comprising at least one optical material within the entire diffuser material and / or on the surface profile of the diffuser polymer.

[0007] In another aspect, a system comprising a light source and the hybrid diffuser is disclosed.

[0008] In an additional aspect, a method of using the system is disclosed, the method comprising: illuminating a light source to emit light from the light source; and receiving the light emitted from the light source at a hybrid diffuser.

[0009] In another aspect, a method of making a hybrid diffuser is disclosed, the method comprising the steps of: providing a mold having a concave surface profile; forming a first layer of charged optical material on the concave surface profile of the mold; and forming a second layer of oppositely charged optical material on the surface of the first layer.

[0010] In another aspect, a method of making a hybrid diffuser is disclosed, the method including the steps of: providing a substrate; depositing a diffuser material comprising at least one optical material using a liquid coating process, the liquid coating process exerting shear forces that align the at least one optical material; curing the deposited diffuser material; and providing the cured diffuser material with a surface profile.

[0011] Additional features and advantages of various embodiments will be set forth in part in the description of the embodiments that follows, and in part will be obvious from this description, or may be learned by the practice of various embodiments. The object and advantages of the various embodiments will be realized and attained by means of the elements and combinations particularly pointed out in the description herein.

[0012] Features of the present invention are illustrated by way of non-limiting example in the following figures, in which like numbers indicate like elements and in which: [Brief explanation of the drawings]

[0013] [Figure 1] FIG. 1 illustrates a hybrid diffuser according to one embodiment of the present invention. [Figure 2] FIG. 1 illustrates a hybrid diffuser according to another embodiment of the present invention. [Figure 3] 3A-B are diagrams illustrating the orientation of the diffuser material and optical materials to create a surface profile. [Figure 4] 4A-B are diagrams illustrating the orientation of the diffuser material and optical materials to create a surface profile. [Figure 5] 5A-B are diagrams illustrating the orientation of the diffuser material and optical materials to create a surface profile. [Figure 6] FIG. 10 illustrates the orientation of the diffuser material and optical materials to create a surface profile. [Figure 7] Figure 7A illustrates a system including a hybrid diffuser according to one embodiment of the present invention, and Figure 7B illustrates a system including a hybrid diffuser according to another embodiment of the present invention. [Figure 8] FIG. 1 shows a mold having a concave surface profile for use in a method according to one aspect of the present invention. [Figure 9] FIG. 1 shows a mold including a first layer of charged optical material and a second layer of oppositely charged optical material. [Figure 10] FIG. 1 illustrates layer formation to form a flat surface. [Figure 11] FIG. 1 illustrates a hybrid diffuser according to one embodiment of the present invention. [Figure 12] Figure 1 shows a hybrid diffuser mounted on a substrate with an optically functional coating. [Figure 13] 13A to 13C are diagrams showing a surface type diffuser and its intensity profile. [Figure 14] 14A and 14B are diagrams showing a volume diffuser and its intensity profile. [Figure 15] 15A-B show the intensity profile of the hybrid diffuser. [Figure 16] Figure 1 shows the polarization of the hybrid diffuser. DETAILED DESCRIPTION OF THE INVENTION

[0014] Detailed Description of the Invention For simplicity and illustrative purposes, the present invention will be described primarily with reference to examples thereof. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be readily apparent that the present invention may be practiced without limitation to these specific details. In other instances, certain methods and structures are not described in order to avoid unnecessarily obscuring the present invention.

[0015] Additionally, the elements shown in the accompanying drawings may include additional components. Some of the components depicted in these drawings may be removed and / or modified without departing from the scope of the present invention. Furthermore, the elements shown in the drawings may not be drawn to scale, and therefore, these elements may have a different size and / or shape than that depicted in the drawings.

[0016] It should be understood that both the foregoing general description and the following detailed description are exemplary and exemplary only and are intended to provide an explanation of various embodiments of the present teachings. Disclosed herein, in its wide variety of embodiments, is a hybrid diffuser 10, which, as shown in FIG. 1, includes: a diffuser material 12 having a flat surface 14 opposite a surface having a surface profile 16; and at least one optical material within the diffuser material 12 and / or on the surface profile 16 of the diffuser material.

[0017] The diffuser material 12 can be any transparent material. The diffuser material 12 can be used as a matrix to contain at least one optical material 18 throughout its entirety. The diffuser material 12 can form a surface profile 16 and / or can assume a shape that includes the surface profile 16. The diffuser material 12 can be any curable polymer. Non-limiting examples of suitable diffuser materials include thermoplastics such as polyesters, polyolefins, polycarbonates, polyamides, polyimides, polyurethanes, acrylics, acrylates, polyvinyl esters, polyethers, polythiols, silicones, fluorocarbons, and their various copolymers; thermosets such as epoxies, polyurethanes, acrylates, melamine formaldehyde, urea formaldehyde, and phenol formaldehyde; energy-curable materials such as acrylates, epoxies, vinyls, vinyl ethers, styrenes, and silanes; and combinations thereof. Additional diffuser materials 12 include, but are not limited to, silanes, siloxanes, titanates, zirconates, aluminates, silicates, phosphazenes, polyborazylenes, and polythiazyls.

[0018] The polymer chains of the diffuser material 12 can be crosslinked and then cured using polymerization techniques. Non-limiting examples of polymerization techniques include photo-induced polymerization, such as free radical polymerization, spectrally sensitized light-induced free radical polymerization, photo-induced cationic polymerization, and photo-induced cycloaddition; electron beam-induced polymerization, such as electron beam (EB)-induced free radical polymerization, EB-induced cationic polymerization, and EB-induced cycloaddition; and thermally induced polymerization, such as thermally induced cationic polymerization. In one embodiment, the diffuser material 12 can be deposited on a substrate 40 or formed into a mold 32 having a concave surface profile, and then crosslinked and / or cured using techniques such as non-radical curing systems, ultraviolet light, infrared light, heat, chemically induced beams, and / or electron beams.

[0019] The diffuser material 12 can have a lower surface, such as a flat surface 14, which can be the interface with the upper surface of the substrate 40. The diffuser material 12 can have a surface with a surface profile, such as a random surface profile, a periodic surface profile, and / or a patterned surface profile. The surface profile 16 can be created by methods such as stamping, embossing, molding (casting, injection molding), or reactive ion etching.

[0020] The surface profile 16 can be defined by the distribution of scattering center heights and sizes. The surface profile of the diffuser material 12 can have a physical thickness greater than 0 nm, i.e., it is not simply a flat top surface of the diffuser material 12. For example, the surface profile 16 of the diffuser material 12 can have a physical thickness sufficient to include microstructures of some depth. The surface profile 16 of the diffuser material 12 can have a physical thickness of, for example, about 5 microns to about 500 microns, about 10 microns to about 200 microns, and, as an additional example, about 40 microns to about 100 microns, including all ranges and subranges therebetween.

[0021] The diffuser material 12 can include at least one optical material 18 within the entire diffuser material 12. The diffuser material 12 can include at least one optical material 18 on a surface profile 16 of the diffuser material 12. The diffuser material 12 can include at least one optical material 18 within the entire diffuser material 12 and on a surface of the diffuser material 12.

[0022] At least one optical material 18 can provide optical functionality not provided by the diffuser material 12 or surface profile 16 alone. Non-limiting examples of properties include, but are not limited to, light scattering, electric and / or magnetic properties, fluorescent properties, IR (infrared) to visible light coverage (low-energy incident light produces high-energy light), electrochromism, thermochromism, wavelength-dependent light absorption, thin film interference, diffractive interference, polarization control, and combinations thereof. The combination of optical functionality provided by the optical material 18 and / or surface profile 16 with non-optical functionality provided by the diffuser material 12 can enable the design of a hybrid diffuser 10 that can respond to external influences such as temperature, pressure, electric and / or magnetic fields, motion, gravity, radiation, etc., and combinations thereof.

[0023] The at least one optical material 18 can be present in an organic phase, an inorganic phase, or a gas phase. The at least one optical material 18 can be in the form of particles (nanoparticles or microparticles), rods 20, wires, fibers, filaments, ribbons, ellipsoids, other shapes, and combinations thereof. In one embodiment, the at least one optical material 18 can be a collection of particles, where the particles range in size, for example, from about 20 nm to about 1000 nm, from about 30 nm to about 900 nm, and additionally, from about 40 nm to about 800 nm. In one embodiment, the at least one optical material 18 can be present in the diffuser material 12 as particles embedded (randomly or specifically positioned) throughout the diffuser material 12, as a layer of particles within the diffuser material 12, or as particles on the surface profile 16 of the diffuser material 12.

[0024] The at least one optical material 18 can be orientable in a field, such as an applied electromagnetic field, as described further below. The at least one optical material 18 can have a shape selected from linear, circular, spiral, and combinations thereof. As shown in FIG. 2 , in one embodiment, the at least one optical material 18 can be oriented in a configuration selected from linear, circular, spiral, and combinations thereof. In particular, the metal rods can be oriented in relation to the orientation of the surface profile 16. The dimensions of the rods, as well as the diffuser material 12, can affect the amount of energy transmitted by the hybrid diffuser 10. As described in more detail below, the metal rods 20 can be dispersed within the diffuser material 12 and oriented in a magnetic field before the diffuser material 12 is cured.

[0025] The diffuser material 12 can include a plurality of elongated particles of optical material 18 throughout the diffuser material 12, which can respond to an external electric field. The elongated particles of optical material 18 can be polarized and can align parallel to an applied electric field. For example, polarized ellipsoidal particles can align with their major axes parallel to the electric field. This alignment is independent of whether the elongated particles are solid or hollow.

[0026] Non-limiting examples of elongated particles of optical material 18 include wires, fibers, filaments, ribbons, ellipsoids, other shapes, and combinations thereof. Elongated particles of optical material 18 can be fabricated using electrospinning and / or centrifugal spinning from a variety of optical materials, such as polymers, ceramics, metals, and combinations thereof. In one embodiment, the elongated particles of optical material 18 can be fibers, such as hollow fibers, having diameters ranging from nanometers to micrometers, e.g., 10 nm to 10 μm. In the form of hollow fibers, the elongated particles of optical material 18 can include one or more channels, e.g., two, three, four, or five channels. Hybrid diffusers 10 containing elongated particles of optical material 18 throughout the diffuser material 12 can produce a wide variety of optical responses. As shown in FIG. 6, elongated particles, such as hollow and solid elongated particles of optical material 18, can be aligned perpendicular to the surface of the hybrid diffuser 10. In this way, the angle of incident light can have a strong effect on the optical properties of the hybrid diffuser 10.

[0027] The diffuser material 12 can be porous, i.e., it can contain spaces throughout the diffuser material 12 that can be void of at least one optical material 18. The at least one optical material 18 can have a size that can cause Mie scattering (which occurs when the size of the molecules, particles, or voids is larger than the wavelength of the incident light) or Rayleigh scattering (which occurs when the wavelength of the incident light is larger than the size of the molecules, particles, or voids).

[0028] In one embodiment, when present on the surface profile 16, the at least one optical material 18 can have a smaller size than the at least one optical material 18 present throughout the diffuser material 12 as shown in FIG. 1. In this manner, the at least one optical material 18 is present on the surface profile 16 in the form of a plurality of protrusions that are small relative to the surface profile 16. These protrusions can be designed to provide anti-reflective properties. Additionally, the optical material 18 on the surface profile 16 can provide superhydrophobicity (e.g., self-cleaning / lotus effect).

[0029] The surface profile 16 can be formed using elongated particles of optical material 18, such as solid and / or hollow elongated structures, as shown in FIGS. 3A and 3B. The coating density can be varied, e.g., increased, by successively depositing elongated particles of optical material 18 of different diameters to create the surface profile 16 of the diffuser material 12, as shown in FIGS. 4A and 4B. The surface profile 16 can also be achieved by successive layers of elongated particles of optical material 18, where different layers are oriented in different directions. As shown in FIGS. 5A and 5B, a first layer includes elongated particles of optical material 18 having a first (larger) diameter and oriented in a first direction, a second layer includes elongated particles of optical material 18 having a second (smaller) diameter and oriented in the first direction, and a third layer includes elongated particles of optical material 18 having a third (smallest) diameter and oriented in a second direction different from the first direction. It can be understood that solid and hollow elongated particles of optical material 18 of any combination of diameters and materials can be used in any orientation. These variables can be selected based on the specific photonic, mechanical, tribological, and catalytic properties of the hybrid diffuser 10.

[0030] At least one optical material 18 can be a metallic material. Non-limiting examples of metallic materials include aluminum, palladium, silver, titanium, iron, cobalt, copper, tin, gold, nickel, alloys thereof, metal compounds containing carbon, oxygen, nitrogen, and combinations thereof, and combinations thereof.

[0031] At least one optical material 18 can be inorganic and, for example, present in the form of a layer or layer-forming particles within the hybrid diffuser 10. Non-limiting examples of suitable inorganic materials include SiO2, TiO2, Al2O3, ZrO2, WO3, VO5, ITO, Ta2O5, CeO2, Y2O3, ZnS, In2O3, La2O3, MgO, Nd2O3, Pr6O 11 , Fe2O3, Fe3O4, SiO, SnO2, FeO x, MgF2, AlF3, CeF3, LaF3, LiF, CaF2, cermets, diamond-like carbon, and combinations thereof. Metal oxides include MO x where M is the metal, O is oxygen, and x can be a ratio when used in non-stoichiometric compounds.

[0032] At least one optical material can be a light absorbing material that can function as a uniform or selective absorber at different wavelengths. Non-limiting examples of light absorbing materials include carbon, graphite, silicon, germanium, cermets, metals mixed in a dielectric matrix, Inconel, stainless steel, Hastelloy, and combinations thereof.

[0033] The at least one optical material 18 can be an organic coloring substance. Non-limiting examples of organic coloring substances include perylene, perinone, quinacridone, quinacridonequinone, anthrapyrimidine, anthraquinone, anthanthrone (anthanthrone), benzimidazolone, diazo condensing agent, azo, quinolone, xanthene, azomethine, quinophthalone, indanthrone (indanthrone), phthalocyanine, triallyl carbonium, dioxazine, aminoanthraquinone, isoindoline, diketopyrrolopyrrole, thioindigo, thiazineindigo, isoindoline, isoindolinone, pyranthrone (pyranthrone), isoviolanthrone (isoviolanthrone), miyoshimethane, triarylmethane, and mixtures thereof.

[0034] At least one optical material 18 can be a liquid crystal polymer. This liquid crystal polymer (LCP) can be one or more solidified polymeric liquid crystal components. The LCP can have a viewing-angle-dependent color and can be composed of oriented, three-dimensionally cross-linked materials with a liquid crystal structure having a chiral phase. This LCP structure can be obtained by orienting, then three-dimensionally cross-linking, one or more three-dimensionally cross-linkable liquid crystal materials with a chiral phase, followed by grinding to the desired particle size. The resulting LCP structure is a platelet-shaped particle containing a cross-linked material with a liquid crystal structure (i.e., the polymer or monomer fluid prior to cross-linking was in this liquid crystal-type ordered state). Alternatively, this LCP structure can be formed by coating platelet-shaped particles with a liquid crystal material. This LCP structure can be made from a precursor composition containing at least one nematic compound and at least one chiral dopant compound.

[0035] The hybrid diffuser 10 may also include a functional coating 38. The functional coating 38 may be present on an upper surface, such as the surface profile 16, of the hybrid diffuser 10. The functional coating 38 may provide protective and optical functions in addition to the functions provided by the at least one optical material 18 present in the hybrid diffuser 10.

[0036] The hybrid diffuser 10 can include multilayer optical designs with different optical purposes, such as dichroic filtering, anti-reflection, bypass filtering, etc. The entire hybrid diffuser 10 can be fabricated with a multilayer design based on different particle types of optical material 18. If desired, the particle density of the optical material 18 can vary from layer to layer. Alternatively, each layer can have a different ratio of particles and / or particle sizes. The flexibility of having different types, sizes, distributions, layers, and thicknesses of optical material 18 allows for the fabrication of hybrid diffusers 10 with performance specifically tailored for different wavelengths, intensities, and applications. As an example, an anti-reflection multilayer design with high and low refractive index particles can be integrated into the entire diffuser material 12. The particle density, arrangement, size, optical properties, and layer thickness can be optimized for the wavelength requiring anti-reflection properties. Furthermore, the ability to vary the density of rigid solid particles within the more flexible diffuser material 12 allows the dimensions of the hybrid diffuser 10 to be varied (stretched or compressed), and therefore its optical properties to be tuned. A dichroic diffuser can be integrated into the entire diffuser material 12. In this case, the optical design of the nanoparticle-based high / low index layers can filter not only the spatial distribution, but also some of the desired or undesired light wavelengths.

[0037] 7A and 7B, system 24 can include a light source 26 and hybrid diffuser 10 as described above with respect to Figure 1. Light source 26 can emit light 28 that is received by hybrid diffuser 10. Light source 26 can emit light 28 in the ultraviolet to infrared wavelength range.

[0038] A method of using system 24 includes emitting light 28 from light source 26; and receiving the light emitted from light source 26 at hybrid diffuser 10. In one embodiment, hybrid diffuser 10 can include at least one optical material 18 (e.g., a scattering component) on surface profile 16 and / or within diffuser material 12, which can combine to provide illuminating output 30. The presence of at least one optical material 18 within diffuser material 12 can modify the illuminating output 30 otherwise observed from a surface-type diffuser alone. Simply put, a scattering profile modified by the contribution of a volume-type diffuser can be described as a convolution of the scattering contribution of the surface-type diffuser alone and the scattering contribution of the volume-type diffuser alone. The general result is that the modified scattering profile can exhibit improved uniformity characteristics compared to a surface-type diffuser (as shown in FIG. 13A) or a volume-type diffuser (as shown in FIG. 14A) alone. The hybrid diffuser 10 can include a liquid crystal polymer as at least one optical material 18, which can provide active scattering and polarization control. In one embodiment, the hybrid diffuser 10 can include metal rods as the optical material 18, which can provide passive polarization and intensity control. The hybrid diffuser 10 can be a linear polarizer, a spectral bandgap filter, or a cutoff filter. The hybrid diffuser 10 can also exhibit temperature control because the optical material 18 becomes electrically conductive when present in a field, such as an applied electromagnetic field.

[0039] A method for fabricating a hybrid diffuser is also disclosed, comprising the steps of providing a mold 32 having a concave surface profile; forming a first layer of charged optical material 34 on the concave surface profile of the mold; and forming a second layer of oppositely charged optical material 36 on the surface of the first layer. As shown in FIG. 8, the mold 32 can include a concave surface profile. The mold 32 can be used in a layer-by-layer deposition of optical material 18, where a first layer can be charged optical material 34 and a second layer can be oppositely charged optical material 36, as shown in FIG. 9. The method can include adding additional layers of charged optical material 34 alternating with additional layers of oppositely charged optical material 36 to achieve a flat surface, as shown in FIG. 10. In this manner, a bilayer of (charged / oppositely charged) optical material 18 can be deposited within the mold 32. The bilayer of optical material 18 can be a bilayer of inorganic / organic optical material 18.

[0040] In one embodiment, the method includes filling a mold 32 with diffuser material 12 to obtain a flat surface 14. In this manner, the diffuser material 12 is a liquid and the charged optical material 34 and the oppositely charged optical material 36 can be dispersed within the diffuser material 12.

[0041] The method can include applying a field, such as an electromagnetic field, to the hybrid diffuser 10. The applied field can be selected from an electric field, an electromagnetic field, a magnetic field, a shear field, a gravitational field, and combinations thereof. The applied field can align the optical material 18 within the bulk of the diffuser material 12. For example, metal rods within the bulk of the diffuser material 12 can align in a magnetic field. As an additional example, elongated particles of the optical material 18 within the bulk of the diffuser material 12 can align in an electric field.

[0042] The method can include curing the formed layers (i.e., the first layer, the second layer, and any additional layers). This curing can fix the aligned optical material in an applied field (magnetic or electric field). This curing technique is disclosed above.

[0043] The method may also include removing the mold 32 from the formed and hardened layer, as shown in FIG.

[0044] The method may also include mounting the hybrid diffuser 10 to a substrate 40, as shown in FIG.

[0045] Depending on the application, the method may include applying a functional coating 38 to the surface profile of the hybrid diffuser 10. The functional coating 38 may be applied using a deposition process such as PVD (physical vapor deposition), CVD (chemical vapor deposition), layer-by-layer, ALD (atomic layer deposition), wet chemical precipitation, sol-gel, etc.

[0046] In one embodiment, a method of making a hybrid diffuser 10 is disclosed, comprising the steps of providing a substrate 40; depositing a diffuser material 12 comprising at least one optical material 18 using a liquid coating process, where the liquid coating process exerts shear forces that align the at least one optical material 18; curing the deposited diffuser material 12; and providing a surface profile 16 on the cured diffuser material 12. In this manner, the diffuser material 12 can include elongated particles or rod-shaped liquid crystal polymers, allowing the resulting hybrid diffuser 10 to pass polarized light through a surface-type diffuser. The elongated particles or rod-shaped liquid crystal polymers can be aligned by shear forces induced by the use of a slot die. After evaporation of any solvent and curing of the diffuser material 12, the surface profile 16 can be formed using a mold or by embossing.

[0047] example

[0048] Comparative Example 1—As shown in FIG. 13A, a surface-type diffuser 44 included a diffuser material 12 with a flat surface 14 opposite a surface with a surface profile 16. This surface-type diffuser 44 was a microlens-based surface-type diffuser, and under coherent illumination, produced a rectangular field of view of approximately 37 by 26 degrees as viewed at a detector size of 0.25°, as shown in FIG. 13B. Cross sections through the x and y axes are also shown, as shown in FIG. 13C, where the solid lines are along the wider axis and the dotted lines are along the narrower axis. Several aspects of uniformity were identified. High-frequency components were caused by the presence of speckle. There was also low-frequency nonuniformity, easily identified in terms of lines and stripes that gave the image its particular scattering structure.

[0049] To help minimize the structures observed in Comparative Example 2-Comparative Example 1 and Figures 13B and 13C, a volume diffuser was prepared as shown in Figure 14A. Volume diffuser 46 included a diffuser material 12 having flat surfaces 14 throughout and at least one optical material 18 within the diffuser material. The volume diffuser of Figure 14A produced a scattering profile with a Lorentzian profile, with a full width at half maximum of 4°, as shown in Figure 14B.

[0050] Example 1—A hybrid diffuser 10 was prepared as shown in Figure 1. The total output was calculated as the convolution between the surface and volume diffuser patterns, as shown in Figure 15A. Cross sections through the x and y axes are also shown, as shown in Figure 15B, where the solid line is along the wider axis and the dotted line is along the narrower axis. The final output of the hybrid diffuser 10 provided excellent uniformity. As long as the transmission efficiency of the hybrid diffuser 10 is sufficiently high, the overall transmission efficiency will also be high. As an estimate, assuming that the flat surface 14 of the surface diffuser 44 includes an anti-reflection coating, the transmission efficiency of the surface diffuser 44 was estimated to be 94%. Assuming that the overall transmission efficiency of the volume diffuser 46 is 85%, the transmission efficiency of all components of the hybrid diffuser 10 would be 80%.

[0051] Comparative Example 3—Regarding polarization, the surface-type diffuser 44 shown in FIG. 13A generally provides a polarization state for the incident illumination beam. The volume-type diffuser 46 shown in FIG. 14A generally converts the incident illumination beam 28 into a different polarization state. As shown in FIG. 16, the hybrid diffuser 10 can include metal microrods or metal nanorods oriented along the direction indicated by the arrows. The electric field incident on the rods aligned with the rods is largely absorbed, and only the orthogonal electric field is transmitted.

[0052] From the foregoing description, those skilled in the art will appreciate that the teachings of the present application can be implemented in a variety of forms. Accordingly, while these teachings have been described with reference to specific embodiments and examples thereof, the true scope of the teachings of the present application should not be so limited. Various changes and modifications can be made without departing from the teachings herein.

[0053] The scope of the disclosure should be construed broadly. The present disclosure is intended to disclose equivalents, means, systems, and methods for implementing the devices, operations, and mechanical operations disclosed herein. For each disclosed device, item, method, means, mechanical element, or mechanism, the present disclosure is intended to encompass and teach within that disclosure the equivalents, means, systems, and methods for implementing the numerous aspects, mechanisms, and devices disclosed herein. The claims of this application should likewise be construed broadly. The description of the invention in its numerous embodiments herein is merely exemplary in nature, and thus, variations that do not depart from the gist of the invention are intended to be within the scope of the invention. Such variations should not be considered as departures from the spirit and scope of the invention.

Claims

1. a diffuser material having a flat surface opposite the surface having the surface profile; and at least one optical material, the surface profile is a surface diffuser; A hybrid diffuser, wherein the at least one optical material includes an optical material on the surface profile and an optical material within the bulk of the diffuser material, the at least one optical material including: i) cross-linked liquid crystal polymer structures in the form of platelet-like particles; or ii) an optical material within the bulk in the form of rod-like liquid crystal polymers aligned to polarize light.

2. The hybrid diffuser of claim 1 , wherein the at least one optical material is present in an organic phase, an inorganic phase, or a gas phase.

3. 10. The hybrid diffuser of claim 1, wherein the at least one optical material is a collection of particles, the particles ranging in size from 20 nm to 1000 nm.

4. The hybrid diffuser of claim 1 , wherein the at least one optical material has a shape selected from linear, circular, spiral, and combinations thereof.

5. 10. The hybrid diffuser of claim 1, wherein the liquid crystal polymer has a viewing angle dependent color and is composed of a three-dimensionally cross-linked material with a liquid crystal structure having a chiral phase.

6. the at least one optical material is present on the surface profile in the form of protrusions; the protrusions are small compared to the surface profile; The hybrid diffuser of claim 1 .

7. The hybrid diffuser of claim 1 , wherein the surface profile is defined by a distribution of scattering center heights and sizes.

8. A light source and The hybrid diffuser of claim 1. A system comprising:

9. A method of using a system, comprising: activating a light source to emit light from the light source; receiving light emitted from the light source in a hybrid diffuser according to claim 1; A method comprising:

10. The method of claim 9 , wherein the hybrid diffuser emits light with a modified scattering profile.

11. The method of claim 9 , wherein the hybrid diffuser comprises a liquid crystal polymer, which provides active scattering and polarization control.

12. The method of claim 9 , wherein the hybrid diffuser comprises metal rods, the metal rods providing passive polarization and intensity control.

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