Spectral-selective optical elements

Abstract

An example includes an optical element. The optical element includes a first optical material structure with a first refractive index across a frequency spectrum. The optical element also includes a second optical material structure configured to exhibit a change in refractive index from the first refractive index to a second refractive index across a portion of the frequency spectrum, and a refractive index anomaly corresponding to the change from the second refractive index to the first refractive index along the frequency spectrum. The optical element further includes a diffractive interface corresponding to a non-planar material contact junction between the first optical material structure and the second optical material structure. The diffractive interface can be configured to steer a light beam having a light path through the diffractive interface and having a frequency in the portion of the frequency spectrum in a predetermined manner.

Description

[Technical Field]

[0001] This disclosure relates, in general, to optical systems, and more particularly to spectrally selective optical elements. [Background technology]

[0002] Manipulating electromagnetic waves is becoming increasingly prevalent in a variety of technologies, including healthcare, remote sensing, navigation, and communications. Optical systems may require the ability to manipulate light waves across a broad frequency spectrum, but often only a selected band within this range is needed for the instrument's purposes. Optical systems can utilize optical phenomena to manipulate electromagnetic waves. For example, the Christiansen effect explains the reduction in scattering observed when different materials have the same refractive index. However, when the refractive index differs between two surfaces of nearly identical material, the scattering and wavefront interaction at the interface between these surfaces are amplified in proportion to the difference in refractive index between the surfaces. A diffractive optical control structure that realizes the Christiansen effect typically only serves a useful function across the diffractive optical bandwidth for a useful range of the refractive optical system. Outside the high-efficiency diffraction band, a given diffractive optical control structure can actually degrade the overall optical performance of the optical system, such as by acting as a scattering source that contributes to the background noise of the associated optical instrument. [Overview of the project]

[0003] One example includes an optical element. The optical element includes a first optical material having a first refractive index over a frequency spectrum. The optical element also includes a second optical material structure configured to exhibit refractive index anomalies corresponding to a change in refractive index from the first refractive index to a second refractive index over a portion of the frequency spectrum, and a change in refractive index from the second refractive index to the first refractive index along the frequency spectrum. The optical element further includes a diffraction interface corresponding to a non-planar material contact junction between the first optical material structure and the second optical material structure. The interface can be configured to have an optical path through the diffraction interface and to manipulate a light beam having a frequency over a portion of the frequency spectrum in a predetermined manner.

[0004] Another example includes a method for manufacturing an optical element. The method includes providing a first optical material structure formed from a substrate material and having a first refractive index over a frequency spectrum, and a second optical material structure formed from the substrate material. The method also includes introducing an impurity that affects the refractive index into the second optical material structure to facilitate the manifestation of refractive index anomalies corresponding to the change in refractive index from the first refractive index to the second refractive index over a portion of the frequency spectrum, and the change from the second refractive index to the first refractive index along the frequency spectrum. The method also includes forming a light diffraction structure on one surface of the first and second optical material structures, and forming a complementary structure on the other surface of the first and second optical material structures. The method further includes joining the first and second optical material structures via their surfaces to form a diffraction interface between the first and second optical material structures. The diffraction interface can be configured to manipulate a light beam having a frequency over a portion of the frequency spectrum and having an optical path through the diffraction interface in a predetermined manner.

[0005] Another example includes an optical system. The system includes a first optical element in the optical path of a light beam. The first optical element includes a first optical material structure having a first refractive index over the frequency spectrum. The first optical element also includes a second optical material structure configured to exhibit a first refractive index anomaly corresponding to a change in refractive index from a first refractive index to a second refractive index over a first portion of the frequency spectrum, and a change in refractive index from a second refractive index to a first refractive index along the frequency spectrum. The first optical element further includes a first diffraction interface corresponding to a first non-planar material contact junction between the first optical material structure and the second optical material structure. The first diffraction interface can be configured to manipulate a light beam having a frequency in a first portion of the frequency spectrum in a predetermined manner. The system also includes a second optical element in the optical path of the light beam. The second optical element includes a third optical material structure having a first refractive index over the frequency spectrum. The second optical element also includes a fourth optical material structure configured to exhibit a second refractive index anomaly corresponding to a change in refractive index from a first refractive index to a third refractive index over a second portion of the frequency spectrum, and a change in refractive index from a third refractive index to a first refractive index along the frequency spectrum. The second optical element further includes a second diffraction interface corresponding to a second non-planar material contact junction between the third optical material structure and the fourth optical material structure. The second diffraction interface can be configured to manipulate a light beam having a frequency in the second portion of the frequency spectrum in a predetermined manner. [Brief explanation of the drawing]

[0006] [Figure 1] Figure 1 shows an example of an optical element. [Figure 2] Figure 2 shows another example of an optical element. [Figure 3] Figure 3 shows an example of a graph of the refractive index and diffraction efficiency of an optical element. [Figure 4] Figure 4 shows a diagram illustrating an example of an optical system, along with corresponding graphs of the refractive index and diffraction efficiency of the optical system. [Figure 5] Figure 5 shows an example of a method for manufacturing an optical element. [Modes for carrying out the invention]

[0007] This disclosure relates, in general, to optical systems, and more particularly to spectrally selective optical elements. A spectrally selective optical element (hereinafter referred to as "optical element") can be fabricated to include a first optical material structure and a second optical material structure, each of which corresponds to the same substrate material. The second optical material structure may contain impurities that affect the refractive index, which can facilitate the manifestation of a refractive index anomaly. As described herein, the term "index anomaly" corresponds to a change in refractive index from the nominal index of refraction of the substrate material over a clearly defined spectral range. Such an index anomaly can be generated in various ways, but typically it can be generated by incorporating the absorption characteristics of light at lower wavelengths from a desired location of the index anomaly. This difference can be determined, for example, by the Kramers-Kronig relation.

[0008] For example, the diffraction efficiency of optical elements such as diffractive optical elements (DOEs) can depend on the central design wavelength λ0 and the diffraction order m, where m ranges from 1 to ∞, and the wavelength of light is expressed as follows:

[0009]

number

[0010] For any given substrate material, absorption properties can cause decay within the material. For example, the Kramers-Kronig relation can guarantee that these absorption properties also manifest as changes in refractive index in the material. Many materials have dispersion relations that are well explained by the Sellmeier or Cauchy dispersion models. In the field of ellipsometry, these dispersion models are often reinforced by distributions related to dispersion phenomena caused by specific absorption properties. In such cases, a Lorentz distribution is often incorporated into the total dispersion curve to capture the change in refractive index of the material immediately following a strong absorption property. For example, refractive index anomalies can force optical elements (e.g., DOEs) to operate only near a desired absorption band.

[0011] The product of the Lorentz distribution (e.g., due to an absorber) and the diffractive optical efficiency provides the resulting efficiency of the optical element. To model possible refractive index anomalies, the Lorentz amplitude can be scaled by the magnitude of the refractive index change (e.g., Δn(λ) = n2(λ) - n1(λ), ​​where λ represents the spectral dependence of the refractive indices of media 1 and 2). The magnitude of the refractive index change can indicate the strength of the interaction between the wavefront and the diffracting surface of the optical element. If this difference is negligible, the performance of the optical element can be governed by its behavior as a refractive element. Examples of such optical elements can range from simple ones like windows to more complex ones like aspherical correctors, beam directors, or imaging lenses in telescopes.

[0012] In the described optical element, the first refractive index corresponding to the nominal refractive index of the substrate material changes to a second refractive index over a portion of the frequency spectrum and then returns to the first refractive index along the frequency spectrum. Thus, the second optical material structure can exhibit a different refractive index for a light beam having a wavelength in that portion of the frequency spectrum (e.g., at the wavefront of the light beam). As described herein, the terms "wavelength" and "frequency" are used interchangeably because wavelength and frequency are inversely proportional. Thus, the wavelength of a light beam is described as existing within the frequency spectrum, and the frequency spectrum is described herein with respect to wavelength.

[0013] The first optical material structure and the second optical material structure can be arranged flush with each other in contact. Thus, based on the combination of the first optical material structure and the second optical material structure, a light beam passing through the first optical material structure and the second optical material structure can undergo the Christensen effect. Thus, a light beam having a wavelength outside that portion of the frequency spectrum may not be affected by the optical element. However, a light beam having a wavelength in that portion of the frequency spectrum may undergo scattering (e.g., interaction) between surfaces based on the difference in refractive index between the first optical material structure and the second optical material structure.

[0014] The optical element includes a diffractive interface corresponding to a non-planar material contact junction between the first optical material structure and the second optical material structure. The diffractive interface can manipulate a light beam in a portion of the frequency spectrum where the refractive index is significantly different between the substrate and the doping material. As an example, the optical element can have spectral selectivity with respect to providing a coherent interaction with an optical element resulting from the Christensen effect, which exhibits minimal scattering between two surfaces having the same refractive index and maximum interaction when the refractive index between the substrates is maximum. As a result, the dispersion of light exhibited by the substrate and the doped substrate can be substantially the same anywhere outside the vicinity of the refractive index anomaly spectrum.

[0015] For example, the diffractive interface may be a diffractive optical element or a holographic optical element corresponding to a variety of equivalent optical elements such as a lens (e.g., a concave lens or a convex lens), a grating, a polarizer, an occulting mask, or any other diffractive surface configured to provide a predetermined operation on the optical wavefront. As an example, the diffractive interface can have a diffraction efficiency higher than a predetermined threshold (e.g., about 95%) in a region corresponding to the refractive index anomaly. The interaction of light with the surface is substantially dominated by the diffractive surface only when the dispersion is different between the surfaces.

[0016] Thus, the optical element can provide a predetermined operation on an optical beam having a wavelength in the relevant portion of the frequency spectrum and can be substantially transparent to an optical beam having a wavelength outside the relevant portion of the frequency spectrum. Further, a plurality of distinct optical elements each having a refractive index anomaly associated with a distinct portion of the frequency spectrum can be implemented within an optical system such that different portions of the frequency spectrum of the optical beam can be affected. [[ID=^6]]

[0017] FIG. 1 is a diagram showing an example of an optical element 10. The optical element 10 can be implemented in any of a variety of optical systems that can perform optical imaging. As described herein, the term "optical" with respect to an optical system, an optical beam, and / or optical imaging can refer to the manipulation of electromagnetic radiation over a very broad frequency spectrum (e.g., from below very long wavelength infrared (VLWIR) to beyond ultraviolet (UV)), and thus is not limited to the visible spectrum.

[0018] The optical element 10 includes a first optical material structure 12 and a second optical material structure 14. The first optical material structure 12 has a first refractive index over the frequency spectrum associated with the input optical beam, shown as OPT in the example of FIG. 1. As an example, the input optical beam OPT IN has a first refractive index over the frequency spectrum associated with the input optical beam, shown as OPT in the example of FIG. 1. As an example, the input optical beam OPT INThe optical element 10 may have one or more wavelengths and may have an optical path through it. The second optical material structure 14 contains an impurity 16 that affects the refractive index, configured to exhibit a refractive index anomaly related to the refractive index of the second optical material structure 14. The refractive index anomaly can correspond to a change in refractive index from a first refractive index to a second refractive index over a portion of the frequency spectrum, and a change from a second refractive index to a first refractive index along the frequency spectrum. Thus, as will be described in more detail herein, the refractive index anomaly is based on the Christiansen effect and affects the optical beam OPT IN This can provide diffraction.

[0019] For example, the first optical material structure 12 and the second optical material structure 14 can each contain the same substrate material (e.g., any of various types of glass or glass oxide) so that they can exhibit the same nominal refractive index. The impurities 16 that affect the refractive index can correspond to any of the various materials that can be introduced into the substrate material of the second optical material structure 14 to introduce a refractive index anomaly in a given portion of the frequency spectrum. For example, the impurities 16 that affect the refractive index can correspond to dopant materials, dyes, embedded nanoparticle absorbers, implanted ions, or any other type of material that can be introduced into the substrate material of the second optical material structure 14 to introduce a refractive index anomaly. Thus, the first optical material structure 12 and the second optical material structure 14 can exhibit substantially the same refractive index along the frequency spectrum, except for a given portion of the frequency spectrum corresponding to the refractive index anomaly where the refractive indices of the first optical material structure 12 and the second optical material structure 14 differ. As another example, one of the optical material structures 12 and 14 may be formed from an electro-optic material to provide electro-optic control of the refractive index of one of the optical material structures.

[0020] The optical element 10 also includes a diffraction interface 18 corresponding to the contact junction of the first optical material structure 12 and the second optical material structure 14. As described herein, the diffraction interface 18 is not a physical component in itself, but refers to the plane physical contact interface of the opposing surfaces of the first optical material structure 12 and the second optical material structure 14. For example, the diffraction interface 18 is a lens (e.g., concave or convex), a grating, a polarizer, a diffractive optical element, a holographic optical element, or an optical beam OPT. IN It can correspond to any of the various geometric physical surfaces for providing optical manipulation of the first and second optical material structures, such as any other diffraction surface configured to provide a predetermined diffraction. Thus, the diffraction interface 18 corresponds to a non-planar material contact junction related to the surface of the second optical material structure 14 and the complementary surface of the first optical material structure 12.

[0021] As an example, the diffraction interface 18 can be manufactured based on a physical optical system such that it has a diffraction efficiency greater than a predetermined threshold in the portion of the frequency spectrum that approximately coincides with the portion of the frequency spectrum of the refractive index anomaly. Therefore, the diffraction interface 18 is a light beam OPT having wavelengths present in a predetermined portion of the frequency spectrum. IN It is configured to operate in a predetermined manner. As described herein, the term “operating a light beam” refers to any of the various diffraction-related operations, such as focusing (e.g., as a lens), directing, polarization, filtering, or any other type of optical operation. Thus, the output light beam OPT OUT The output light beam OPT OUT This is the optical beam OPT at the wavelength of the portion of the frequency spectrum based on the combination of refractive index anomaly and diffraction interface 18. IN The output of the optical element 10 may be provided so that optical manipulation can be demonstrated.

[0022] Figure 2 is a diagram showing another example of the optical element 50. The optical element 50 can be implemented in any of various optical systems capable of performing optical imaging. The optical element 50 is shown in the example of Figure 2 as a diagram of the optical element 10 in the example of Figure 1. Therefore, in the following description of the example of Figure 2, the example of Figure 1 is referred to.

[0023] The optical element 50 includes a first optical material structure 52 and a second optical material structure 54. The first optical material structure 52 has a first refractive index across the frequency spectrum associated with the input light beam OPT IN The second optical material structure 54 is shown shaded in the example of Figure 2 to indicate the inclusion of impurities that affect the refractive index, configured to exhibit a refractive index anomaly related to the refractive index of the second optical material structure 54.

[0024] For example, the first optical material structure 52 and the second optical material structure 54 can each include the same substrate material such that the first optical material structure 52 and the second optical material structure 54 can exhibit the same nominal refractive index. Therefore, impurities that affect the refractive index can introduce a refractive index anomaly in a predetermined portion of the frequency spectrum. Therefore, the first optical material structure 52 and the second optical material structure 54 can exhibit substantially the same refractive index along the frequency spectrum, except for a predetermined portion of the frequency spectrum corresponding to the refractive index anomaly where the refractive indices of the first optical material structure 52 and the second optical material structure 54 are different.

[0025] The optical element 50 also includes a diffraction interface 56 corresponding to the contact junction of the first optical material structure 52 and the second optical material structure 54. In the example of Figure 2, the diffraction interface 56This is shown as an etched grating on the surface of one of the first optical material structure 52 and the second optical material structure 54. For example, the other of the first optical material structure 52 and the second optical material structure 54 can be applied to the etched surface via a melting or sputtering process, etc., to provide a complementary surface to the other of the first optical material structure 52 and the second optical material structure 54, and to provide a diffraction interface 56. However, an alternative method can be provided to provide flush contact between the first optical material structure 52 and the second optical material structure 54 in order to form a diffraction interface 56 between them.

[0026] For example, the diffraction interface 56 can be manufactured to have a diffraction efficiency greater than a predetermined threshold (e.g., about 95%) in a portion of the frequency spectrum that substantially coincides with a portion of the frequency spectrum of the refractive index anomaly. For example, the manufacturing of the diffraction interface 56 may include providing physical properties of the diffraction interface 56 that affect a specific band of the frequency spectrum (e.g., relating to the dimensions of the grating of the diffraction interface 56 or other physical aspects), where the specific band substantially corresponds to a portion of the frequency spectrum of the refractive index anomaly. For example, the diffraction interface 56 may have a wavelength λ defined as follows: I It can be patterned to provide a diffractive bandpass Δλ starting from [a certain point].

[0027]

number

[0028] Here, PT corresponds to a predetermined threshold for diffraction efficiency. For example, the diffraction interface 56 can be patterned in a predetermined manner on the surface of one of the first optical material structure 52 and the second optical material structure 54 to provide a diffraction efficiency exceeding a predetermined threshold at a position on the frequency spectrum approximately equal to a predetermined portion of the frequency spectrum of the refractive index anomaly. As another example, an impurity affecting the refractive index can be introduced into the second optical material structure 54 in a predetermined manner to exhibit a refractive index anomaly at a position on the frequency spectrum approximately equal to a predetermined portion of the frequency spectrum of the frequency spectrum where the diffraction efficiency of the diffraction interface 56 is greater than a predetermined threshold.

[0029] Therefore, the diffraction interface 56 is an optical beam OPT having wavelengths present in a predetermined portion of the frequency spectrum. IN It is configured to operate in a predetermined manner. Therefore, the output light beam OPT OUT The output light beam OPT OUT This is the optical beam OPT at the wavelength of the portion of the frequency spectrum based on the combination of refractive index anomaly and diffraction interface 56. IN The output of the optical element 50 may be provided so that optical manipulation can be demonstrated.

[0030] As a result, the optical element 50 can be configured to correct any of the various optical aberrations in the optical system, such as spherical aberration and / or chromatic aberration, or to correct the optical beam OPT IN It can be implemented to provide selective polarization, filtering, or optical path modification of a portion of the frequency band. In addition, the optical element 50 has spectral selectivity with respect to a portion of the frequency band and is transparent to all other wavelengths on the frequency spectrum. Thus, the optical element 50 can be incorporated into an optical system to correct the wavelength of that portion of the frequency band without adversely affecting the rest of the frequency band, as is typical when other types of corrective optics are incorporated into a typical optical system. Furthermore, since the optical element 50 is formed from only two substrate material structures, the optical element 50 is significantly smaller and lighter than typical optical corrective devices.

[0031] Figure 3 is a diagram 100 showing an example of a refractive index graph, generally shown as 102, and a diffraction efficiency graph, generally shown as 104, for an optical element. For example, the refractive index graph 102 and the diffraction efficiency graph 104 can correspond to optical elements 10 and / or 50 in the respective examples of Figures 1 and 2. Therefore, the following example in Figure 3 refers to the examples in Figures 1 and 2.

[0032] Diagram 100 shows the frequency spectrum with respect to wavelength λ, with the refractive index graph 102 and the diffraction efficiency graph 104 plotted along it. The frequency spectrum λ starts at wavelength λ0, which corresponds to the longest wavelength on the frequency spectrum λ, and the frequency increases / wavelength decreases. The refractive index graph 102 shows the refractive indices of the first optical material structure 52 and the second optical material structure 54, respectively, with the refractive index of the first optical material structure 52 shown as a solid line and the refractive index of the second optical material structure 54 shown as a dashed line. Starting at wavelength λ0, the refractive indices of the first optical material structure 52 and the second optical material structure 54 are approximately equal and decrease from the initial value to the nominal value "A".

[0033] At wavelength λ1, the refractive index of the second optical material structure 54 increases compared to the refractive index of the first optical material structure 52. The difference in refractive index between the first optical material structure 52 and the second optical material structure 54 can be based on the introduction of a refractive index anomaly in the second optical material structure 54, shown at 106 in the example in Figure 3, due to impurities that affect the refractive index. Therefore, even though the first optical material structure 52 and the second optical material structure 54 are manufactured from the same substrate material, the second optical material structure 54 can have a different refractive index in a portion of the frequency spectrum λ compared to the first optical material structure 52, based on impurities that affect the refractive index. As a result, the optical beam OPT INThe first optical material structure 52 can be subjected to the Christiansen effect in the portion of the frequency spectrum λ corresponding to the refractive index anomaly 106. The refractive index of the second optical material structure 54 is shown to increase to a maximum value "B" and then decrease back to approximately value "A" at wavelength λ4. The refractive index of the first optical material structure 52 remains approximately constant between wavelengths λ1 and λ4. At frequencies greater than wavelength λ4, and therefore wavelengths less than wavelength λ4, the refractive indices of the first optical material structure 52 and the second optical material structure 54 are approximately the same.

[0034] As mentioned above, the diffraction interface 56 may be patterned to provide a diffraction efficiency greater than a predetermined threshold for a portion of the frequency spectrum λ. In the example of Figure 3, the diffraction interface 56 may be manufactured in a predetermined manner to provide a diffraction efficiency greater than a predetermined threshold, shown as approximately 95% in the example of Figure 3, for a portion of the frequency spectrum λ. In the example of Figure 3, the portion of the frequency spectrum λ where the diffraction efficiency is greater than approximately 95% lies between wavelengths λ2 and λ3, and thus defines the diffraction bandpass Δλ of the diffraction interface 56. As an example, the diffraction interface 56 may be manufactured such that the diffraction bandpass Δλ is approximately centered on the refractive index anomaly 106. As a result, the diffraction interface 56 and the refractive index anomaly 106 work together to provide an optical beam OPT within the diffraction bandpass Δλ. IN Manipulate the wavelength.

[0035] As described above, the optical element 50 can correspond to one of several optical elements in an optical system. For example, multiple optical elements 50 can be implemented in an optical system to affect multiple different parts of a frequency band, for example, to correct optical aberrations in different parts of a frequency band. Therefore, multiple optical elements 50 can be implemented along a given optical path to affect multiple different parts of the frequency spectrum λ.

[0036] Figure 4 shows an exemplary diagram of the optical system 152, along with the corresponding graphs of refractive index (shown overall as 154) and diffraction efficiency (shown overall as 156). The optical system 152 can be implemented in any of the various optical imaging environments. In the example in Figure 4, the optical system 152 uses an input light beam OPT IN The optical path includes a first optical element 158 ​​and a second optical element 160. As described herein, the optical elements 158 and 160 can provide selective optical operation for each distinct portion of the frequency spectrum λ.

[0037] The optical element 158 ​​includes a first optical material structure 162 and a second optical material structure 164. The first optical material structure 162 has a first refractive index over the frequency spectrum λ. The second optical material structure 164 is configured to exhibit a refractive index anomaly, shown at 166 in graph 154, related to the refractive index of the second optical material structure 164, and is shown in shaded form in the example of Figure 4 to show the inclusion of impurities that affect the refractive index. The optical element 158 ​​also includes a diffraction interface 168 corresponding to the contact junction of the first optical material structure 162 and the second optical material structure 164. The diffraction interface 168 may have a diffraction bandpass Δλ1 substantially matching the refractive index anomaly 166. Thus, the optical element 158 ​​is arranged substantially similarly to the optical element 50 in the example of Figure 2. The first optical element 158 ​​is based on optical manipulation of wavelengths within the diffraction bandpass Δλ1 substantially matching the refractive index anomaly 166, etc., of the input light beam OPT IN Based on mid-beam OPT PTH We can provide this.

[0038] Similarly, the optical element 160 includes a first optical material structure 168 and a second optical material structure 170. The first optical material structure 168 has a first refractive index over the frequency spectrum λ. The second optical material structure 170 is shaded in the example of Figure 4 to show the inclusion of impurities that affect the refractive index, configured to exhibit a refractive index anomaly shown as 172 in Graph 154, related to the refractive index of the second optical material structure 170. As an example, the impurities that affect the refractive index in the second optical material structure 170 may be different from the impurities that affect the refractive index in the second optical material structure 164 in order to provide a refractive index anomaly 172 in different parts of the frequency spectrum λ. The optical element 160 also includes a diffraction interface 174 corresponding to the contact junction of the first optical material structure 168 and the second optical material structure 170. The diffraction interface 174 may have a diffraction bandpass Δλ2 that substantially coincides with the refractive index anomaly 172. As an example, the physical properties of diffraction interfaces 168 and 174 result in a diffraction bandpath Δλ1 that is different from the diffraction bandpath Δλ2, and therefore the diffraction bandpaths Δλ1 and Δλ2 can be substantially different so as not to overlap. Thus, the optical element 160 is arranged substantially similarly to the optical element 50 in the example of Figure 2. The second optical element 160 is based on optical manipulation of wavelengths in the diffraction bandpath Δλ2 that substantially coincide with the refractive index anomaly 172, such as the mid-light beam OPT. PTH Output light beam OPT based on OUT We can provide this.

[0039] As previously mentioned, diagram 150 shows graph 162 of the refractive index and graph 164 of the diffraction efficiency plotted against the frequency spectrum λ. The frequency spectrum λ starts at wavelength λ0, corresponding to the longest wavelength on the frequency spectrum λ, and the frequency increases / wavelength decreases. The graph of refractive index 162 shows the refractive index of optical material structures 162 and 164, as well as optical material structures 168 and 170, respectively. The refractive index of optical material structures 162 and 168, corresponding to the nominal refractive index of the substrate material for optical material structures 162, 164, 168, and 170, is shown as a solid line, the refractive index of optical material structure 164 is shown as a dashed line, and the refractive index of optical material structure 170 is shown as a dotted line. Starting from wavelength λ0, the refractive indexes of the respective optical material structures 162, 164, 168, and 170 are approximately equal and decrease from the initial value to the nominal value "A".

[0040] At wavelength λ1, the refractive index of optical material structure 164 increases relative to that of optical material structures 162, 168, and 170. The difference in refractive index between optical material structure 164 and optical material structures 162, 168, and 170 can be attributed to the introduction of refractive index anomaly 166. It has been shown that the refractive index of optical material structure 164 increases to a maximum value "B" and then decreases back to approximately value "A" at wavelength λ4. The refractive indexes of optical material structures 162, 168, and 170 remain approximately constant between wavelengths λ1 and λ4. At wavelength λ5, the refractive index of optical material structure 170 increases relative to that of optical material structures 162, 164, and 168. The difference in refractive index between optical material structure 170 and optical material structures 162, 164, and 168 can be attributed to the introduction of refractive index anomaly 172. The refractive index of optical material structure 170 has been shown to increase to a maximum value "B" and then decrease back to approximately value "A" at wavelength λ8. The refractive indices of optical material structures 162, 164, and 168 remain approximately constant between wavelengths λ5 and λ8. It should be understood that the increase in refractive index is not limited to being equal for each of the refractive index anomalies 166 and 172 (e.g., to a maximum value "B"), but can be different based on different impurities affecting the refractive index.

[0041] As described above, the diffraction interfaces 168 and 174 may each be patterned to provide a diffraction efficiency greater than a predetermined threshold for each portion of the frequency spectrum λ. In the example of Figure 4, the diffraction interfaces 168 and 174 may each be manufactured in a predetermined manner to provide a diffraction efficiency greater than a predetermined threshold, shown as approximately 95% in the example of Figure 4, for each distinct portion of the frequency spectrum λ.

[0042] In the example in Figure 4, the portion of the frequency spectrum λ at diffraction interface 168 where the diffraction efficiency is greater than approximately 95% lies between wavelengths λ2 and λ3, thus defining the diffraction bandpass Δλ1 of diffraction interface 168. Similarly, the portion of the frequency spectrum λ at diffraction interface 174 where the diffraction efficiency is greater than approximately 95% lies between wavelengths λ6 and λ7, thus defining the diffraction bandpass Δλ2 of diffraction interface 174. As an example, diffraction interface 168 may be manufactured such that the diffraction bandpass Δλ1 is approximately centered around refractive index anomaly 166, and diffraction interface 174 may be manufactured such that the diffraction bandpass Δλ2 is approximately centered around refractive index anomaly 174. As a result, diffraction interface 168 and refractive index anomaly 166 work together to form an optical beam OPT within diffraction bandpass Δλ1. IN By manipulating the wavelength, the diffraction interface 174 and the refractive index anomaly 172 work together to produce an optical beam OPT within the diffraction bandpass Δλ2. PTH Manipulate the wavelength.

[0043] The optical system 152 is not limited to the two optical elements 154 and 156, but may include one or more additional optical elements, each associated with a distinct portion of the frequency spectrum λ and which may be associated with one or more distinct optical paths of the optical system. Thus, multiple spectral aberrations can be selectively corrected and / or introduced in each associated optical system. Accordingly, the optical elements described herein can be flexibly implemented to provide desired optical results across the frequency spectrum λ.

[0044] In light of the structural and functional features described above, the methods according to various aspects of the exemplary embodiments will be better understood with reference to Figure 5. For the sake of simplicity, the methods in Figure 5 are shown and described as being performed sequentially, but it should be understood and recognized that the exemplary embodiments are not limited by the order in which they are shown, as some aspects may occur in a different order than those shown and described herein, and / or simultaneously with other aspects, according to the exemplary embodiments. Furthermore, not all illustrated features are required to carry out the method according to one aspect of the exemplary embodiments.

[0045] Figure 5 shows an example of a method 200 for manufacturing an optical element (e.g., optical element 10). In 202, a first optical material structure (e.g., first optical material structure 12) is provided, formed from a substrate material and having a first refractive index over a frequency spectrum (e.g., frequency spectrum λ). In 204, a second optical material structure (e.g., second optical material structure 14) is provided, formed from a substrate material. In 206, an impurity affecting the refractive index (e.g., an impurity affecting the refractive index 16) is introduced into the second optical material structure to facilitate the manifestation of refractive index anomalies (e.g., refractive index anomaly 106) corresponding to the change in refractive index from the first to the second refractive index over a portion of the frequency spectrum and the change from the second to the first refractive index along the frequency spectrum. In 208, a photodiffraction structure is formed on one surface of the first and second optical material structures. In 210, a complementary structure is formed on the other surface of the first and second optical material structures. In 212, the first and second optical material structures are joined via the surfaces of the first and second optical material structures, forming a diffraction interface (e.g., diffraction interface 18) between the first and second optical material structures.

[0046] The above is an example of the present disclosure. Of course, it is impossible to describe every conceivable combination of components or methods for the purpose of illustrating the present disclosure, but those skilled in the art will recognize that many further combinations and substitutions of the present disclosure are possible. Accordingly, the present disclosure is intended to encompass all such changes, modifications, and variations that fall within the scope of the application, including the appended claims. Furthermore, whereever the disclosure or claims describe a “a, an,” “a first,” “another” element, or equivalents thereof, it should be construed as including one or more such elements, and does not require or exclude two or more such elements. As used herein, the terms “includes, including” mean to include without limitation. The terms “based on” mean to be based at least in part. The technical concepts included in this disclosure are described below as an addendum. (Note 1) It is an optical element, A first optical material structure having a first refractive index across the frequency spectrum, A second optical material structure configured to exhibit refractive index anomalies corresponding to a change in refractive index from the first refractive index to the second refractive index over a portion of the frequency spectrum, and a change in refractive index from the second refractive index to the first refractive index along the frequency spectrum, The diffraction interface corresponding to the non-planar material contact junction between the first optical material structure and the second optical material structure, An element comprising, wherein the diffraction interface has an optical path passing through the diffraction interface and is configured to manipulate a light beam having the frequency of the portion of the frequency spectrum in a predetermined manner. (Note 2) The element according to Appendix 1, wherein the first optical material structure and the second optical material structure each contain the same substrate material, and the second optical material structure contains an impurity that affects the refractive index, configured to facilitate the occurrence of the refractive index anomaly with respect to the second optical material structure. (Note 3) The element according to Appendix 2, wherein the impurity affecting the refractive index is a dopant material introduced into the substrate material of the second optical material structure. (Note 4) The element according to Appendix 2, wherein the impurity affecting the refractive index is a dye introduced into the substrate material of the second optical material structure. (Note 5) The element according to Appendix 2, wherein the impurity affecting the refractive index is ion implantation introduced into the substrate material of the second optical material structure. (Note 6) The element according to Appendix 1, wherein the diffraction interface corresponds to a photo-control structure patterned on one surface of the first optical material structure and the second optical material structure, and a complementary photo-control structure patterned on the opposing surface of the other of the first optical material structure and the second optical material structure. (Note 7) The diffraction interface corresponds to one of the elements described in Appendix 1, namely a diffractive optical element, a holographic optical element, a polarizer, or a lens. (Note 8) The device according to Appendix 1, wherein the diffraction interface is designed to provide a diffraction efficiency greater than a predetermined threshold over a diffraction bandpass which is substantially the same as the portion of the frequency spectrum. (Note 9) The element described in Appendix 8, wherein the predetermined threshold for the diffraction efficiency is approximately 95% or more. (Note 10) An optical system comprising the optical element described in Appendix 1, wherein the optical element is a first optical element, and the optical system further comprises a second optical element in the optical path of the light beam. (Note 11) The second optical element is, A third optical material structure having the first refractive index over the frequency spectrum, A fourth optical material structure configured to exhibit a change in refractive index from the first refractive index to the third refractive index over a second portion of the frequency spectrum, and a second refractive index anomaly corresponding to the change from the third refractive index to the first refractive index along the frequency spectrum, A second diffraction interface corresponding to a second non-planar material contact junction between the third optical material structure and the fourth optical material structure, The optical system according to Appendix 10, comprising, wherein the second diffraction interface is configured to manipulate the light beam having a frequency in the second portion of the frequency spectrum and having an optical path through the second diffraction interface in a predetermined manner. (Note 12) The diffraction interface is a shielding mask, as described in Appendix 1. (Note 13) The diffraction interface includes a structured anti-reflective coating, as described in Appendix 1. (Note 14) The element according to Appendix 1, wherein the substrate material of the second optical material structure is formed from an electro-optic material to provide electro-optic control of the second refractive index. (Note 15) The element according to Appendix 1, wherein the diffraction interface is defined by a physical optical system for manipulating the light beam in the predetermined manner. (Note 16) A method for manufacturing optical elements, To provide a first optical material structure formed from a substrate material and having a first refractive index across the frequency spectrum, To provide a second optical material structure formed from the aforementioned substrate material, To facilitate the occurrence of refractive index anomalies corresponding to the change in refractive index from the first refractive index to the second refractive index over a portion of the frequency spectrum, and the change in refractive index from the second refractive index to the first refractive index along the frequency spectrum, impurities that affect the refractive index are introduced into the second optical material structure. To form a light diffraction structure on the surface of one of the first optical material structure and the second optical material structure, To form a complementary structure on the surface of the other of the first optical material structure and the second optical material structure, The first optical material structure and the second optical material structure are joined together via the surfaces of the first and second optical material structures to form a diffraction interface between the first and second optical material structures. A method comprising, wherein the diffraction interface is configured to have an optical path through the diffraction interface and to manipulate a light beam having the frequency of the portion of the frequency spectrum in a predetermined manner. (Note 17) The method according to Appendix 16, wherein introducing an impurity that affects the refractive index includes doping the substrate material of the second optical material structure with an impurity that affects the refractive index. (Note 18) The method according to Appendix 16, wherein forming the optical diffraction structure includes etching one of a diffractive optical element, a holographic optical element, a polarizer, or an optical grating onto the surface of the second optical material structure. (Note 19) The method according to Appendix 16, wherein forming the complementary structure includes sputtering the other of the first and second optical material structures onto the optical diffraction structure on the surface of one of the first and second optical material structures. (Note 20) The method according to Appendix 16, wherein forming the optical diffraction structure includes shaping the optical diffraction structure to provide a diffraction efficiency greater than a predetermined threshold over a second portion of the frequency spectrum that defines the diffraction bandpass of the diffraction interface, and the method further includes matching the diffraction bandpass to a first portion of the frequency spectrum. (Note 21) A first optical element in the optical path of a light beam, A first optical material structure having a first refractive index across the frequency spectrum, A second optical material structure configured to exhibit a change in refractive index from the first refractive index to the second refractive index over a first portion of the frequency spectrum, and a first refractive index anomaly corresponding to the change from the second refractive index to the first refractive index along the frequency spectrum, A first diffraction interface corresponding to a first non-planar material contact junction between the first optical material structure and the second optical material structure, wherein the first diffraction interface is configured to manipulate the light beam having a frequency in the first portion of the frequency spectrum in a predetermined manner. A first optical element including, A second optical element located in the optical path of the light beam, A third optical material structure having the first refractive index over the frequency spectrum, A fourth optical material structure configured to exhibit a change in refractive index from the first refractive index to the third refractive index over a second portion of the frequency spectrum, and a second refractive index anomaly corresponding to the change from the third refractive index to the first refractive index along the frequency spectrum, A second diffraction interface corresponding to a second non-planar material contact junction between the third optical material structure and the fourth optical material structure, the second diffraction interface configured to manipulate the light beam having a frequency in the second portion of the frequency spectrum in a predetermined manner. A second optical element including An optical system equipped with [the necessary components]. (Note 22) The system as described in Appendix 21, wherein the first optical material structure and the second optical material structure each comprise the same first substrate material, the third optical material structure and the fourth optical material structure each comprise the same second substrate material, the second optical material structure comprises a first impurity affecting the refractive index configured to facilitate the occurrence of the refractive index anomaly for the second optical material structure, and the fourth optical material structure comprises a second impurity affecting the refractive index configured to facilitate the occurrence of the refractive index anomaly for the fourth optical material structure. (Note 23) The element as described in Appendix 21, wherein the first diffraction interface corresponds to a first optical control structure patterned on one surface of the first optical material structure and the second optical material structure, and a complementary optical control structure patterned on the opposing surface of the other of the first optical material structure and the second optical material structure, and the second diffraction interface corresponds to a second optical control structure patterned on one surface of the third optical material structure and the fourth optical material structure, and a complementary optical control structure patterned on the opposing surface of the other of the third optical material structure and the fourth optical material structure. (Note 24) The system as described in Appendix 21, wherein the first diffraction interface is designed to provide a diffraction efficiency greater than a first predetermined threshold over a first diffraction bandpass which is substantially the same as the first portion of the frequency spectrum, and the second diffraction interface is designed to provide a diffraction efficiency greater than a second predetermined threshold over a second diffraction bandpass which is substantially the same as the second portion of the frequency spectrum. (Note 25) An optical element, A first optical substrate having a predetermined refractive index dispersion curve over a first transmission spectral range, A second optical substrate exhibits refractive index anomalies with respect to the first substrate over a second transmission spectral range within the first transmission spectral range, and has substantially the same dispersion as the first optical substrate outside the second transmission spectral range, A complementary geometric beam control interface between the first optical substrate and the second optical substrate, corresponding to a non-planar material contact junction between the first optical material structure and the second optical material structure, and An element comprising a complementary geometric beam control interface configured to manipulate a light beam having an optical path through the interface in a predetermined manner. (Note 26) The optical element comprises a plurality of pairs of optical substrates, each having a plurality of complementary geometric beam control interfaces between them, wherein the second transmission spectral range associated with each of the plurality of pairs of optical substrates does not overlap with the second transmission spectral range of any other pair of optical substrates among the plurality of pairs of optical substrates, as described in Appendix 25. (Note 27) The element described in Appendix 2, wherein the impurities affecting the refractive index are spectrally absorbing nanoparticles, and their density determines the spectral absorptivity of the material.

Claims

1. A first optical element in the optical path of a light beam, A second optical element in the optical path of the light beam and An optical system comprising, The first optical element is, A first optical material structure having a first refractive index across the frequency spectrum, A second optical material structure configured to exhibit a change in refractive index from the first refractive index to the second refractive index over a first portion of the frequency spectrum, and a first refractive index anomaly corresponding to the change from the second refractive index to the first refractive index along the frequency spectrum, A first diffraction interface corresponding to a first non-planar material contact junction between the first optical material structure and the second optical material structure, and The first diffraction interface is configured to manipulate the light beam having a frequency in the first portion of the frequency spectrum in a predetermined manner, The second optical element is, A third optical material structure having the first refractive index over the frequency spectrum, A fourth optical material structure configured to exhibit a change in refractive index from the first refractive index to the third refractive index over a second portion of the frequency spectrum, and a second refractive index anomaly corresponding to the change from the third refractive index to the first refractive index along the frequency spectrum, A second diffraction interface corresponding to the second non-planar material contact junction between the third optical material structure and the fourth optical material structure, A system comprising, wherein the second diffraction interface is configured to manipulate the light beam having a frequency in the second portion of the frequency spectrum in a predetermined manner.

2. The system according to claim 1, wherein the first optical material structure and the second optical material structure each comprise the same first substrate material, the third optical material structure and the fourth optical material structure each comprise the same second substrate material, the second optical material structure comprises a first impurity affecting the refractive index configured to facilitate the occurrence of the first refractive index anomaly with respect to the second optical material structure, and the fourth optical material structure comprises a second impurity affecting the refractive index configured to facilitate the occurrence of the second refractive index anomaly with respect to the fourth optical material structure.

3. The system according to claim 2, wherein the first impurity affecting the refractive index is one of a dopant material, a dye, and an ion implanter introduced into the substrate material of the second optical material structure, and the second impurity affecting the refractive index is one of a dopant material, a dye, and an ion implanter introduced into the substrate material of the fourth optical material structure.

4. The system according to claim 1, wherein the first diffraction interface corresponds to a photo-control structure patterned on one surface of the first optical material structure and the second optical material structure, and a complementary photo-control structure patterned on the opposing surface of the other of the first optical material structure and the second optical material structure, and the second diffraction interface corresponds to a photo-control structure patterned on one surface of the third optical material structure and the fourth optical material structure, and a complementary photo-control structure patterned on the opposing surface of the other of the third optical material structure and the fourth optical material structure.

5. The system according to claim 1, wherein the first diffraction interface and the second diffraction interface each correspond to one of a diffractive optical element, a holographic optical element, a polarizer, or a lens.

6. The system according to claim 1, wherein the first diffraction interface is designed to provide a diffraction efficiency greater than a predetermined threshold over a diffraction bandpass which is substantially the same as the first portion of the frequency spectrum, and the second diffraction interface is designed to provide a diffraction efficiency greater than a predetermined threshold over a diffraction bandpass which is substantially the same as the second portion of the frequency spectrum.

7. The system according to claim 1, wherein the first diffraction interface and the second diffraction interface are shielding masks.

8. The system according to claim 1, wherein the first diffraction interface and the second diffraction interface each include a structured anti-reflective coating.

9. The system according to claim 1, wherein the substrate material of the second optical material structure is formed from an electro-optic material to provide electro-optic control of the second refractive index, and the substrate material of the fourth optical material structure is formed from an electro-optic material to provide electro-optic control of the third refractive index.

10. The system according to claim 1, wherein the first diffraction interface and the second diffraction interface are defined by a physical optical system for manipulating the light beam in the predetermined manner.

11. A method for manufacturing an optical system, To provide a first optical material structure formed from a first substrate material and having a first refractive index over the frequency spectrum, To provide a second optical material structure formed from the first substrate material, To facilitate the occurrence of a first refractive index anomaly corresponding to the change in refractive index from the first refractive index to the second refractive index over a first portion of the frequency spectrum, and the change in refractive index from the second refractive index to the first refractive index along the frequency spectrum, a first impurity that affects the refractive index is introduced into the second optical material structure. A first optical diffraction structure is formed on the surface of one of the first optical material structure and the second optical material structure. Forming a first complementary structure on the surface of the other of the first optical material structure and the second optical material structure, The first optical material structure and the second optical material structure are joined together via the surfaces of the first and second optical material structures to form a first optical element including a first diffraction interface. The first diffraction interface corresponds to a first non-planar material contact junction between the first optical material structure and the second optical material structure of the first optical element, and the first diffraction interface is configured to manipulate a light beam having a frequency in the first portion of the frequency spectrum having an optical path through the first diffraction interface in a predetermined manner, the method being To provide a third optical material structure formed from a second substrate material and having the first refractive index over the frequency spectrum, To provide a fourth optical material structure for a second optical element formed from the second substrate material, To facilitate the occurrence of a second refractive index anomaly corresponding to the change in refractive index from the first refractive index to the third refractive index over a second portion of the frequency spectrum, and the change in refractive index from the third refractive index to the first refractive index along the frequency spectrum, a second impurity that affects the refractive index is introduced into the fourth optical material structure. A second optical diffraction structure is formed on the surface of one of the third optical material structure and the fourth optical material structure. Forming a second complementary structure on the surface of the other of the third optical material structure and the fourth optical material structure, The third optical material structure and the fourth optical material structure are joined together via the surfaces of the third and fourth optical material structures to form a second optical element including a second diffraction interface. A method comprising, wherein the second diffraction interface corresponds to a second non-planar material contact junction between the third optical material structure and the fourth optical material structure of the second optical element, and the second diffraction interface is configured to manipulate the light beam having the optical path through the second diffraction interface and having the frequency of the second portion of the frequency spectrum in a predetermined manner.

12. The method according to claim 11, wherein introducing at least one of a first impurity affecting the refractive index and a second impurity affecting the refractive index includes doping at least one of the first substrate material of the second optical material structure and the second substrate material of the fourth optical material structure with the impurity affecting the refractive index.

13. The method according to claim 11, wherein forming at least one of the first optical diffraction structure and the second optical diffraction structure comprises etching one of a diffractive optical element, a holographic optical element, a polarizer, or an optical grating onto at least one of the surfaces of the second optical material structure and the fourth optical material structure.

14. The method according to claim 11, wherein forming at least one of the first complementary structure and the second complementary structure includes sputtering at least one of the first optical material structure and the other of the second optical material structure onto the first optical diffraction structure on a given surface of one of the first optical material structure and the second optical material structure, and sputtering at least one of the third optical material structure and the other of the fourth optical material structure onto the second optical diffraction structure on a given surface of one of the third optical material structure and the fourth optical material structure.

15. The method according to claim 11, wherein forming the first optical diffraction structure and at least one of the second optical diffraction structure provides a diffraction efficiency greater than a predetermined threshold over the second portion of the frequency spectrum that defines at least one diffraction bandpass of the first diffraction interface and the second diffraction interface, the method further comprising matching the diffraction bandpass to the first portion of the frequency spectrum.

Images