High density interconnects with 3D broadband electrooptic infrared components

Abstract

Embodiments of the present disclosure include optical elements and methods of forming the same using light-based patterning in solidified molten halide material. Other embodiments include systems that include such optical elements. The light-based patterning may be performed, for example, by forming silver-comprising nanostructure inclusions in a solidified silver halide film using ultraviolet (UV) laser exposure.

Description

HIGH DENSITY INTERCONNECTS WITH 3D BROADBAND ELECTROOPTIC INFRARED COMPONENTSCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of and priority from U.S. Provisional Patent Application Serial No. 63 / 663,463, filed June 24, 2024, and entitled, “HIGH DENSITY INTERCONNECTS WITH 3D BROADBAND ELECTROOPTIC INFRARED COMPONENTS.” The disclosure of the prior application is considered part of and hereby incorporated by reference in its entirety in the disclosure of this application.STATEMENT OF GOVERNMENT INTEREST

[0002] This invention was made with Government support under contract 80NSSC23CA092, awarded by National Aeronautics and Space Administration (NASA). The Government has certain rights in the Invention.BACKGROUND

[0003] The present disclosure is related to infrared (IR) optical and photonic systems, and more specifically, to broadband infrared optical components and systems with operating wavelengths in the range of approximately 1-25 microns (gm). There is a growing need to expand photonics capabilities into mid-IR and longwave-IR bands. However, the lack of highspeed modulators, detectors, or other components makes it challenging to deliver cost-effective solutions, e.g., for telecommunications, environmental sensing, or medical diagnostics. Microgravity purification and enhancement of the uniformity of the materials is considered essential for low-loss, high-density, 3D integration of electrical, optical and photonic components.BRIEF DESCRIPTION OF THE DRAWINGS

[0004] FIG. 1 illustrates an example process for fabricating an optical element in accordance with embodiments of the present disclosure.

[0005] FIGS. 2A-2D illustrate example images of materials produced in accordance with embodiments herein as compared with known techniques.

[0006] FIGS. 3A-3B illustrate transmission plots, for example lightguides formed from a solidified halide melt.

[0007] FIG. 3B illustrates performance of a molten-process silver halide sample as compared with an extruded polycrystalline sample.

[0008] FIGS. 4A-4C illustrate an example process of patterning areas of nanostructures within a host material in accordance with embodiments of the present disclosure.

[0009] FIGS. 5A-5C illustrate examples of nanostructure inclusions inside a light guide formed of solidified halide film.

[0010] FIG. 6 illustrates an example system incorporating the optical element formed by the process of FIGS. 4A-4C.

[0011] FIGS. 7A-7B illustrate example broadband infrared metamaterial modulators (BIMMs), in accordance with embodiments of the present disclosure.

[0012] FIG. 8 illustrates an example laser- written nanostructure-based sensor device in accordance with aspects of the present disclosure.

[0013] FIG. 9 illustrates an example IR imaging system that includes a sensor chip comprising sensing pixels in accordance with embodiments of the present disclosure.

[0014] FIG. 10 illustrates another example sensor chip of the present disclosure.DETAILED DESCRIPTION

[0015] Embodiments herein include infrared (IR) optical or photonic elements that incorporate molten halide materials, and methods for manufacturing the same. Such optical elements may provide low loss, broadband transmission of infrared optical signals. For instance, processes disclosed can fabricating silver halide-based devices that provide high homogeneity, low scattering, and small grain size, and may provide a unique mid-wave infrared (MWIR) and / or long-wave infrared (LWIR) low-loss transparency window for wavelengths between approximately 0.5 microns to 25 microns.

[0016] Some of the optical or photonic elements disclosed herein may be manufactured by laser-writing nanostructures (which may also be referred to as quantum dots (QDs) in some instances) inside a host material (e.g., a silver halide material that includes silver (Ag) and a halogen such as bromine (Br), chlorine (Cl), iodine (I), or fluorine (F), such as AgCl(i-X)Brx). Examples of optical / photonic elements that can be fabricated using techniques of the present disclosure include, for example, high-frequency (e.g., 40GB / s) metamaterial-based modulatorsfor free-space optical (FSO) communication in the MWTR and / or LWIR regions and Broadband Infrared Metamaterial Modulators (BIMMs).

[0017] Thermal imaging, optical communications, chemical sensing and medical diagnostics using broadband infrared solutions are rapidly expanding and maturing industries. Readily available optical materials that are transparent in an extended infrared spectral range (e.g., 1-20 microns) are typically environmentally sensitive, structurally unstable, toxic and / or are not mechanically strong. Moreover, the industry-standard processing methods, including Outside Vapor Deposition (OVD), fiber drawing from a preform, and fusion splicing, are not readily available for broadband infrared transmissive devices. Further, material purification methods, component fabrication methods, and scalable manufacturing technologies are not fully developed, therefore limiting the use of such materials and devices.

[0018] Optical elements of the present disclosure may include molten halide materials, such as molten core optical fibers or waveguides. In embodiments herein, such optical elements may be formed from non-fluoride halide materials, such as chlorides and bromides, which can offer an improved transmission at longer infrared wavelengths as opposed to traditional halide materials (e.g., fluoride-based halides such as ZBLAN (which includes ZrF4, BaF2, LaFa, AlFa and NaF)) while also being less chemically aggressive. Silver chloride and silver bromide polycrystalline fibers are not very toxic, commercially available, and multimode polycrystalline infrared (PIR) fibers, made from AgCl(i-X)Brxsilver halides, serve as a broadband infrared solution covering the spectral range from approximately 3-17 microns. It has been reported that reducing the rod diameter increases scattering in single crystals of AgClBr and extruded optical fibers. This loss has been attributed to pores with an average radius of 0.4-0.6 microns, consistent with theoretical models of cation vacancies localized at charged dislocations.

[0019] Silver halide crystals are typically produced from a molten composition in a fused silica glass or borosilicate glass container. However, silver halide has been problematic for use in molten core fabrication techniques, as the formation of bubbles at the interface of the container may occur with silver halide melts, requiring the removal of the outer crystal layer at the end of the process. Furthermore, currently available fabrication methods for silver halide fibers suffer from excessive scattering loss due to crystal formation and non-uniformity of the core-cladding interface.

[0020] Thus, optical elements of the present disclosure may be fabricated by melting poly crystalline optical fibers with established material purity, and then slowly cooling the melt without formation of the crystal phase. The halide material used may be silver halide (AgCl(i-X)Brx, e.g., where x is between approximately 0.4-0.8, e.g., AgClo.25Bro.75 or AgClo.sBro. 5), or may be another type of halide material, such as, for example, CsI, CsBr, TIBr, T1C1, and KC1, as described in “Infrared Fiber Optics” by P. Klicek and G. Sigel, 1989, which is incorporated herein by reference. Optical elements fabricated with this approach may allow for low loss broadband infrared transmission, e.g., from approximately 0.5 microns to approximately 25 microns.

[0021] For example, some embodiments of the present disclosure may include lightguides and optical fibers that are fabricated using a molten silver halide material, with the resultant lightguide / fiber core having a substantially isotropic composition (as shown, for example, in FIGS. 2A, 2C) as opposed to the non-isotropic composition of current poly crystalline halide cores that have substantial grain size and visible grain boundaries under microscope (as shown, for example, in FIGS. 2B, 2D). A substantially isotropic composition, as used herein, may refer to the solidified halide composition not having microscopic features that are comparable in size with the operating wavelength of an optical element (e.g., does not have grains larger than 0.5-1 um) and / or the processing wavelength for fabrication of light-induced modifications of the material. Because of the substantially isotropic composition of the solidified molten halide material, optical elements of the present disclosure do not exhibit nearly as much scattering as conventional halide core optical elements.

[0022] An alkaline glass cladding with a glass transition temperature that is comparable with a melting temperature or a glass transition temperature of a halide core material may be used. For instance, in some embodiments, soda-lime glass may be used as a cladding or lightguide substrate material. Another type of glass may be used in other embodiments, e.g., borosilicate glass. Further, in some embodiments, another type of substrate may be used, such as, for example, a diamond or sodium chloride substrate.

[0023] A contacting surface of the glass cladding / substrate may be treated with an ion exchange process that suppresses the reaction of the cladding with the halide melt. For example, ion exchange in a salt melt containing silver nitrate may be used for treating the contacting surface of the glass. Halide melts that include silver bromide and / or silver chloride may solidifyinto transparent glass-like elements with reduced scattering in the passivated containment. In some embodiments, the glass may be etched with an argon plasma or with hydrofluoric acid to modify the glass surface prior to exposure with the halide melt. Optical fibers can thus be fabricated using a passivated outer cladding and a molten halide core via a fiber drawing process.

[0024] The halide lightguides / cores produced by such a process may exhibit a substantially isotropic structure with reduced crystalline scattering at shorter wavelengths. Differential calorimetry measurements of some samples may indicate that the substantially isotropic halide core material does not remain in a glassy state, e.g., may not exhibit glass transition at a glass transition temperature. In addition, optical waveguides (also referred to as lightguides in some cases) with halide cores fabricated with this approach may demonstrate a larger infrared transmission of wavelengths, e.g., from approximately 0.5 microns to greater than 25 microns. In some instances, certain processing optimizations, e.g., ground-based or microgravity -based purification processes, along with material optimization (e.g., doping of the silver halide with rare earth ions, such as Er, Ho, Cr, Ce, Tm, Yb, or Nd to modify the photosensitivity), can allow for ultra-low insertion loss infrared lightguides. In some embodiments, for example, microgravity processing can be implemented to purify the halide materials, which can further reduce insertion loss of the resultant fiber / lightguide by suppressing crystallization and phase separation. In addition, microgravity processing may increase the doping concentrations of active ions in the halide host material.

[0025] FIG. 1 illustrates an example process 100 for fabricating an optical element in accordance with embodiments of the present disclosure. Although particular operations are shown in FIG. 1, the process 100 may include additional, fewer, or other operations than those shown. In addition, although shown as separate operations in FIG. 1, certain of the operations (or portions thereof) may be performed simultaneously. In certain embodiments, optical elements may include lightguides that have diameters or cross-sectional measurements of less than 100 um, which may be useful for broadband infrared transmission.

[0026] At 110, a retaining element for receiving or maintaining a halide melt is formed. In some embodiments, the retaining element may be a glass substrate (e.g., soda lime glass) for forming a planar lightguide, while in other embodiments, a glass cladding tube may be used as the retaining element to fabricate molten core optical fibers with halide cores. Creation of the retaining element may include, for example, creating a groove or other type of pattern in a planarglass substrate, e.g., for implementation of a planar optical waveguide structure, or fabrication of a tapered capillary for creation of a tapered optical fiber waveguide.

[0027] At 120, one or more surfaces of the retaining element are treated. This may include passivating the surfaces that are to be in contact with the halide melt material. The passivation may include an ion exchange process. The ion exchange process may implement a silver ion exchange, which may enhance wetting properties with the halide melt to be used. The ion exchange may be performed at a temperature between approximately 220C - 400°C at a duration between approximately 2 minutes - 6 hours. After the completion of the ion exchange process, the retaining element may be cooled down, rinsed in water, and then dehydrated using alcohol. Surface passivation may be useful to avoid the typical interaction issues seen between glass and molten halide materials (e.g., bubble formation); however, such issues may not be present with certain types of substrate materials and accordingly, surface passivation might not be performed in such cases.

[0028] At 130, a halide material is melted (e.g., in a low moisture and low oxygen environment) until molten, and at 140, the molten halide material is flowed or otherwise dispensed into the treated retaining element. In certain embodiments, the halide melt material may be doped with elements that provide additional functionalities to lightguides, such as optical amplification and photosensitivity. The molten halide material may be placed into contact with and cover the ion exchanged surface of the retaining element by a wetting / wicking effect, which may allow for a good surface quality for the lightguide and may completely fill any preformed capillaries and grooves with small cross-sections using surface tension and capillary action. In some embodiments, a capillary action may be used to dispense the molten halide material or otherwise fill the retaining element. Such a process has the benefit of dispensing a high-quality molten halide material while leaving any potential material contaminants at the area of melting, potentially minimizing the presence of contaminants in the formed lightguide.

[0029] At 150, the melt-filled retaining element is cooled, e.g., by setting it into a cooling configuration. For example, where a glass capillary tube is used as the retaining element, the glass capillary may be drawn and cooled down to form a molten core fiber. In another embodiment, supporting substrates may be aligned and placed against one another, setting the interface protections for the molten halide material therebetween and protecting its surfaces for the subsequent cooling that occurs (which results in solidification of the halide material tobecome the resultant lightguide). In some embodiments, the solidification of the halide melt may be performed in a microgravity environment, which may improve the quality of light guiding material or increase a concentration of functional dopants (when present).

[0030] At 160, areas of the lightguide are patterned with light exposure, e.g., ultraviolet laser patterning, which may produce areas inside the solidified halide material that include precipitated nanostructures. For example, exposure of the solidified halide material to a focused UV laser light source (with a wavelength between approximately 10 nm and 400 nm) may create elongated nanostructure inclusions in a silver halide hots material that exhibit dichroism. The duration of the light exposure may influence the number of nanostructures that are formed in an exposed area (and possibly, the size of such nanostructures). Accordingly, the duration of light exposure may be used as a tuning parameter for aspects of the optical element to be formed. In certain cases, one area of a host material may be patterned to include nanostructures that are suitable for electrical conduction, while another area of the host material may be patterned to include nanostructures that are suitable for optical applications. FIGS. 4A-4C illustrate an example process of patterning areas of nanostructures within a host material, and FIGS. 5A-5C illustrate examples of nanostructure inclusions inside a light guide formed of solidified halide film. Each of these is described in more detail further below.

[0031] At 170, post-processing of the optical element may be performed. This can include etching away a glass retaining element or other material or annealing the halide lightguide to reduce insertion loss. In some embodiments, a halide lightguide may be coated with a suitable cladding material using techniques known to those skilled in the art. In other embodiments, post-processing can include annealing of the halide fiber core to minimize its scattering loss after drawing. In some embodiments, the lightguide may be also bonded to a new substrate that is different from the initial retaining element, e.g., a material or element with broadband infrared transmission as opposed to a supporting element comprising soda lime glass.

[0032] In some embodiments, this can also include heating or annealing the optical element. Heating / annealing the optical element may cause for growth of the nanostructures formed in the host material. Thus, the duration of both the light exposure and / or post-processing heating may be used to optimize optical characteristics of the final optical element. For example, the dichroic ratio of a polarizer may be optimized for a desired infrared wavelength using thisprocess. Similar laser exposure of lower intensity and thermal post-treatment with suppressed silver precipitation can also be used for Bragg grating formation.

[0033] Further, in some embodiments, post-processing may include heating the optical element to remove the patterned areas of nanostructures. In particular, while heating the hots material after patterning can cause growth of the precipitated nanostructures in the host material, additional heating can actually cause the nanostructures to reduce in size or otherwise no longer be in the host material. Thus, the post-processing step can include heating to reduce the size of the nanostructures, or even remove the nanostructures (e.g., if an optical element needs to be reconfigured or otherwise modified in some way).

[0034] At 180, the resulting optical element can be integrated into a multi-functional lightwave circuit or system, which may include additional optical components, e.g., light sources, detectors, isolators, circulators, modulators, nonlinear converters, Bragg reflectors and / or polarizers to achieve the desired functionality of the final assembly. In some embodiments, a halide melt solidified between two planar glass substrates may result in a planar layer of halide material. The halide material can be separated from at least one of the glass substrates mechanically or by etching away the glass. The use of a glass substrate with a grove pattern can provide a ridge waveguide structure after filling the groves with the halide melt and etching away the glass substrate. Subsequently bonding the waveguide structure onto mechanically stable and low-loss material for support may enable infrared photonic lightguide circuits for various applications.

[0035] FIGS. 2A-2D illustrate example images of materials produced in accordance with embodiments herein as compared with known techniques. In particular, these figures illustrate SEM images of a first sample of AgCl / Br fabricated by solidifying a halide melt against a second sample of AgCl / Br produced by an extrusion process of poly crystalline AgCl / Br. FIG. 2A illustrates the first sample under x4,000 magnification, FIG. 2B illustrates the second AgCl / Br sample under x4,000 magnification, FIG. 2C illustrates the first sample under x 18,000 magnification, and FIG. 2D illustrates the second sample under xl 8,000 magnification. The first sample has a substantially isotropic composition (as shown in FIGS. 2A, 2C), as opposed to the non-isotropic composition of the extruded polycrystalline sample, which has substantial grain boundaries (as shown in FIGS. 2B, 2D).

[0036] FIGS. 3 A-3B illustrate transmission plots 300 A, 300B for example lightguides formed from a solidified halide melt. As shown in FIG. 3A, silver halide lightguide samples produced in accordance with embodiments herein may offer broadband transmission from approximately 0.5 microns to over 25 microns. FIG. 3B illustrates performance of a molten- process silver halide sample as compared with an extruded polycrystalline sample. As shown, a solidified molten halide core can provide an approximately 40dB / cm increase in transmission around wavelengths of approximately 500nm as compared with an extruded polycrystalline core. This may be due to suppression of pores and polycrystalline grain boundaries in the solidified molten core, which can noticeably reduce scattering and improve optical transmission over the extruded polycrystalline core, especially at shorter wavelengths as shown.

[0037] FIGS. 4A-4C illustrate an example process 400 of patterning areas of nanostructures within a host material in accordance with embodiments of the present disclosure. The process 400 may include additional, fewer, or other operations than those shown. In addition, operations in the process 400 may be performed in a different order than shown. For instance, some of the operations shown may be performed simultaneously, in whole or in part. Further, some of the operations of the process 400 may include sub-operations, which may be performed serially or simultaneously, or in another manner. The process 400 may be used to fabricate various optical elements, including, for example, sub -wavelength plasmonic metamaterial (MM) waveguides.

[0038] Referring first to FIG. 4 A, a patterning operation is performed on a host material 402 using a light source 401. The patterning may be performed by light exposure, e.g., laserwriting using a high-power ultraviolet (UV) (e.g., with approximately 400 nm wavelength) laser. The host material may be a broadband infrared (IR) transmitting material, such as a solidified halide material (e.g., AgCl / Br) film, which may include doping in some embodiments. The light exposure by the light source 401 precipitates nano-scale structures (“nanostructures”, which may be referred to as quantum dots (QDs) in some instances) in the areas 404A, 404B of the host material 402 exposed to the light source 401. That is, the light exposure by the light source 401 causes the nanostructures to be formed in the areas 404 of the host material 402. In some cases, the nanostructures may be plasmonic nanostructures. The size of the nanostructures may be at least approximately an order of magnitude less than the wavelength of visible or infrared (IR) light. For example, the nanostructures may be on the order of approximately 30-100nm in size.Where the host material 402 is a silver halide material as described herein, the nanostructures may include silver, e.g., may be silver particles or may be a semi-silver composition that has not fully oxidized. In some embodiments, the light source 401 may provide an output that combines the light of a blue / UV laser and the light of infrared fiber laser into a single beam, which could be useful for light exposure of the host material 402.

[0039] FIGS. 5A-5C illustrate examples of nanostructure inclusions 504 inside a solidified halide (AgBr / Cl) film 502 after light exposure. In particular, FIG. 5A shows a high magnification image of the film exposure with high intensity light, that creates a variation of properties across the exposed region of the film, FIG. 5B shows a silver plasmonic structure with uniform properties across the exposed region after a moderate amount of UV exposure, and FIG. 5C shows a silver plasmonic structure after thermal post-processing and additional UV exposure. This provides for manufacturing a wide variety of photonic devices, e.g., devices for detection, or 3D high density electrical and optical interconnects that include sub-wavelength plasmonic structures embedded therein along with integrated, unexposed regions of the film that function as low-loss waveguides. Such an advantageous feature facilitates the fabrication of modulators, 3D interconnects and detectors, or other devices while providing additional flexibility in positioning the constituent parts.

[0040] Referring now to FIG. 4B, post processing steps are performed after the initial light exposure shown in FIG. 4A. The post-processing may include operations that alter certain characteristics of the host material 402 and / or the exposed areas 404A, 404B. The postprocessing may include thermal treatment, e.g., annealing, or in some cases, additional light exposure of certain areas. The post-processing can be performed, for example, to tune plasmonic resonance to an operating wavelength of a specific MWIR / LWIR transmitter. Then, as shown in FIG. 4C, additional light exposure may be performed in the to form additional nanostructures in the areas 404C, 404D exposed by the light source 401. Additional post-processing operations, e.g., additional annealing operations, may be performed after the additional light exposure shown in FIG. 4C.

[0041] It will be understood that each of the areas 404 may be patterned to have particular densities or sizes of nanostructures therein, e.g., based on the duration of the exposure to the light source 401 and / or heating after patterning. The patterning may be performed for each area to give that area particular electrical or optical characteristics. For instance, one or more ofthe laser-induced nanostructure areas 404A-D may be configured or implemented to handle optical light signals similarly to planar light circuits known in the art, and operate as any one of light guides, splitters, combiners, micro-ring resonators, multiplexors, mode-coupling devices in a three-dimensional (3D) volume of the optical element 410. Other areas may be configured to conduct electrical signals, e.g., those areas may be patterned to have a higher density of nanostructures therein such that the areas become electrically conductive.

[0042] In the example shown, the areas 404A, 404B have been processed such that the inclusions are suitable for electrical conduction, while the areas 404C, 404D have been patterned to provide particular optical characteristics. For instance, the inclusions in the area 404C may be used as a resonator (e.g., as a detector) or can be used as a modulator or multiplexor / de- multiplexor of light passing through the area 404C. The area 404D may be used as a Bragg grating, e.g., as shown in FIG. 6 and described further below.

[0043] Various or certain aspects of the process 400 may be repeated, if necessary or desired. For example, additional light exposure(s) and / or additional post-processing operations may be performed as needed. In any scenario, the process 400 yields an optical element 410 that can be included in a larger optical system, such as the system shown in FIG. 6 and described further below.

[0044] FIG. 6 illustrates an example system 600 incorporating the optical element 410 formed by the process 400 of FIGS. 4A-4C. The system 600 includes an interconnect carrier board 602 to which the optical element 410 is coupled, along with a light source 604 and processing circuitry 606. The interconnect carrier board 602 may be a printed circuit board (PCB) that includes various electrical, mechanical, and / or optical connections and / or components for interconnecting the optical element 410, the light source 604, the processing circuitry 606, and other components of the system 600. The light source 604 may include any suitable light source, such as a light emitting diode (LED), LED array, or laser. The processing circuitry 606 may include electronic or optical processing circuitry. For example, in some embodiments, the processing circuitry 606 may include modulator driver circuitry and / or optical receiver circuitry. In the example shown, the optical element 410 includes nanostructures in the area 404C that functions as an optical resonator or modulator and nanostructures in the area 404D that functions as a Bragg grating. The optical element 410 also includes nanostructures in the areas 404A, 404Bthat serve as electrical conduction paths between the resonator / modulator area 404C and the processing circuitry 606 (through the conductive leads 603, 605).

[0045] The light source 604 may produce a transmit beam 608 that passes through the optical element 410 as shown, as well as an additional optical element 610 coupled to an end of the optical element 410 opposite the light source 604. The optical element 610 may include broadband IR transmitting optics, e.g., a lens, mirror, or grating, which may be formed from a solidified halide melt. A receive beam 609 also passes through the optical element 610 (in an opposite direction of the transmit beam 608 as shown), and through the areas 404C, which may function as a detector for certain wavelengths and generate electrical signals to the processing circuitry 606 based on the detections.

[0046] The system 600 may, in certain instances, be configured as a photonic integrated circuit (PIC) that operates as an optical transponder for optical communication systems, such as intra-datacenter links or satellite communications. The transmission wavelength range of the light source 604 may be between approximately 0.5 - 25 microns, which allows efficient bandwidth utilization of the optical spectrum. The system 600 may, in certain instances, operate as a sensor, for example, as a sensor in lidar for, e.g., autonomous vehicle or self-driving car applications. The sensor may have higher resilience to weather conditions than those currently available. Further, in some instances, the system 600 can operate as a sensor for chemical or biomedical specimens, examples of which may include environmental monitoring, in-line chemical process control with fiber optic probes, or analysis of biomedical material for cancer diagnostics.

[0047] FIGS. 7A-7B illustrate example broadband infrared metamaterial modulators (BIMMs) 700, 750 in accordance with embodiments of the present disclosure. FIG. 7A illustrates a perspective view of the BIMM 700, while FIG. 7B illustrates a side cross-sectional view of the BIMM 750. In each example, the BIMM includes a lightguide (710, 760) formed on a substrate 702, 752). In some embodiments, the substrate 702 may be glass (e.g. soda lime glass as described above), while in other embodiments, the substrate may be diamond or sodium chloride. The lightguide 710, 760 may be formed of a solidified halide material (e.g., AgBr / Cl) as described herein. Further, the lightguides include areas of nanostructure inclusions (712, 762), which may be formed by light exposure of the halide lightguide material as described herein. The example BIMM 700 includes horizontally-oriented nanostructure inclusions, while the BIMM750 includes vertically-oriented nanostructure inclusions as shown. In both examples, suitable electro-optic materials (e.g., polymers) could be used as optional claddings for an optical halide core of the lightguides. In operation, an input CW light signal 740 (which may be in the MWIR or LWIR wavelength range) enters the lightguide 710 at one end, and the BIMM 700 modulates the light signal to provide an alternating current (AC) (e.g., a radio frequency (RF)) modulated output light signal 745. The BIMM 750 may operate in a similar manner.

[0048] To modulate the light, each example includes electrodes (704, 706, 754, 756) that are positioned adjacent to the lightguide, and the electrodes may be used to tune various aspects of the BIMMs 700, 750. The BIMM 700 includes a planar, set of electrodes 704, 706 on opposite sides of the lightguide 710 (with the inclusions 712 being positioned between the electrodes 704, 706), In contrast, the BIMM 750 includes a vertically-stacked pair of electrodes 754, 756 with at least a portion of the nanostructure inclusions 762 positioned between the electrodes 754, 756. In some embodiments, the electrode 756 may be a microstrip over a ground plane electrode 754. The BIMM 750 includes a planarizing layer 755 between the electrodes 754, 756, which can allow for forming of the microstrip electrode 756.

[0049] In the example shown in FIG. 7A, the electrodes 704, 706 are coupled to an AC voltage source 720 as well as a DC voltage source 721. Similarly, in the example shown in FIG. 7B, the electrodes 754, 754 are coupled to an AC voltage source 770. In some embodiments, the plasmonic metamaterial resonance of the BIMMs may be tuned by applying an AC electric field to the electrodes (e.g., an RF AC voltage), which can achieve electro-optical modulation of MWIR or LWIR light for high-speed transmission modulation. In particular, the nanostructure inclusions may collectively form an absorber with an electrically tunable edge of spectral absorption. By biasing the modulator to a wavelength of operation (e.g., in the MWIR / LWIR regions) and applying a high-speed (RF) voltage to the plasmonic structure, amplitude modulation of an electro-absorption may be accomplished. The example shown in FIG. 7B is driven by a vertical electric-field component and compatible with a microstrip (vertically- stacked) electrode structure, while the example shown in FIG. 7A requires a horizontal electricfield component and compatible with a planar electrode structure (e.g., either a Co-Planar Strip (CPS) layout or a Co-Planar Waveguide (CPW) layout). DC bias of the half-wave voltage and the maximum modulation depth are achievable with available GHz-range RF drivers for select a design for optimization of its RF operation and implementation.

[0050] In some cases, profiled regions of coalesced silver can be fabricated for tapered transitions between a (regular) optical waveguide section and a plasmonic region to reduce coupling loss between the optical waveguide mode and the plasmonic mode.

[0051] In some embodiments, the BIMMs 700, 750 may be configured similar to the hybrid modulator design described in K. Ooi et al, “Ultracompact vanadium dioxide dual-mode plasmonic waveguide electroabsorption modulator,” Nanophotonics, 2(1), pp. 13 - 19, 2013 (using a hybrid plasmonic mode) could be used with multiple quantum dot layers, to operate also at shorter wavelengths (e.g., 1,550 nm). The use of solidified molten halide (e.g., AgBr / Cl) material waveguides as disclosed herein may extend the operation of such a device to the MWIR / LWIR regions.

[0052] In certain embodiments, the BIMMs 700, 750 may be used to modulate a light source, such as, for example, a quantum cascade laser (QCL). In addition, the BIMMs 700, 750 may be used as high-speed optical modulators for free-space optical communications in MWIR and LWIR spectral bands. For example, low-loss waveguides integrated with plasmonic subwavelengths structures may be produced and can be subsequently incorporated into modulator designs that are optimized to meet desired performance requirements. Fabrication may include: (1) fabrication of waveguides optimized for low-loss operation in the MWIR and LWIR regions and compatible with efficient sub-wavelength plasmonic (SWP) structures, (2) integration of the waveguides with the SWP structures and optimization of their aggregate performance, and / or (3) packaging of modulator chips and optimization of their performance to specific desired operating wavelengths by post-processing.

[0053] A plasmonic structure may require an interface between a dielectric material and a highly conductive material (e.g., a metal or doped semiconductor). While conventional approaches require a separate step of deposition / patteming of a conductive material film, embodiments herein utilize the controllable UV irradiation with subsequent thermal treatment for coalescing silver, thereby growing / writing wires and electrodes within an AgBr / Cl film.

[0054] Both uniform plasmonic structures and modulators with defined plasmonic nanoresonator meta-structures / surfaces (MMs) and a slow-light regime of operation have been demonstrated. A plasmonic modulator can be designed to predominantly modulate either the real part of reflective index (phase modulator) or its imaginary part (electro-absorption). Phase modulators may require additional passive waveguide sections to make up an interferometer(commonly of a Mach-Zehnder layout) to convert a phase modulation into an amplitude modulation. Hence, the electro-absorption type may be viewed as the preferred option (barring unacceptably high parasitic phase modulation accompanying such intensity modulation).

[0055] While aspects of the present disclosure could be used for optical communications systems, in other instances, aspects of the present disclosure could be used for other types of optical systems, such as, for example, endoscopes and endoscope systems. Furthermore, aspects of the present disclosure could be used for infrared imaging and high-speed detection.

[0056] For instance, plasmon-enhanced Quantum Dot (QD) based sensors may be a cost- effective approach for thermal LWIR imaging. However, a reliable manufacturing process for these QD sensor materials has not been reported. Aspects of the present disclosure may be used to fabricate Plasmonic Infrared Focal (PIF) Plane Arrays with transmission of wavelengths from approximately 0.5 microns to 25 microns, or higher. In particular, a plasmonic QD focal plane array can be formed in a halide host material by light exposure as described above. Thermal post-processing of the plasmonic QD array can be employed to increase the size of the QDs or to fine-tune the array’s sensitivity to the desired LWIR spectral range. A resulting PIF chip can then be integrated with LWIR optics and further integrated into an imaging senor package.

[0057] Enhanced plasticity at elevated temperatures and broadband transmission of silver halide host material provide a unique opportunity to integrate PIF plane array and silver halide optics into a single monolithic assembly. High refractive index of silver halides in combination with all solid-state assembly design provides the ultimate reduction of size, weight and power for the thermal sensors that will be ideally suited for small UAS (Unmanned Aircraft System) platforms / applications. Furthermore, processing temperatures for silver halide chips are comparable with processing temperatures of standard PCB assemblies. Low-cost sensor elements of the present disclosure could be added to PCBs using industry-standard pick and place machines and then processed using standard PCB assembly equipment, such as reflow ovens.

[0058] The sensors may be fabricated using a laser marking station with a UV laser. Gold electrodes on support substrates can be patterned to achieve a simplified Readout Integrated Circuit (ROIC). The testing of the detectors can be performed using readily available IR laser sources, for example, those with wavelengths of between approximately 980nm and 1550nm. The results of the testing can be then used to further optimize / trim / post-process the sensors foroptimal LWIR operation. The polycrystalline fiber delivery can be used to direct the light to the sensor at LWIR wavelength range.

[0059] FIG. 8 illustrates an example laser-written nanostructure-based sensor device 800 in accordance with aspects of the present disclosure. The device 800 includes a ROIC 802 with pixel electrodes 803 thereon. The ROIC 802 includes circuitry to interconnect optical components with electrical components, e.g., to generate signals detected by the pixel electrodes 803 to electrical signals that can then be used by other electrical circuitry (e.g., a processor). The device 800 further includes a first layer 804 of nanostructures within a solidified halide melt, and a second layer 806 of nanostructures within a solidified halide melt. Each layer may be formed as described above. Each of the layers 804, 806 may be configured with different sizes or densities of nanostructures therein, e g., to detect different wavelengths of light. For example, the layer 804 may detect SWIR light and the layer 806 may detect MWIR light; or the layer 804 may detect MWIR light and the layer 806 may detect LWIR light. In other embodiments, the device 800 may include fewer or additional layers than just 804, 806. For example, the device 800 may include three layers of nanostructures within a solidified halide melt, to respectively detect SWIR, MWIR, and LWIR light similar to the layers 911-913 described below.

[0060] The device 800 also includes a transparent electrode 808 above the layers 804, 806 and a transparent encapsulant material layer 810 above the electrode 808. Although not illustrated, in some embodiments, the device 800 may include another layer of pixel electrodes between the layers 804, 806, which may provide for sensing of each respective layer of 804, 806. That is, the additional layer of pixel electrodes between the layers 804, 806 would provide sensing of light based on the capability of the layer 804, while the pixel electrodes 803 would provide sensing of light based on the capability of the layer 806. In certain embodiments, the device 800 may be used for infrared sensing or imaging applications. For example, the device 800 may be used as the sensor chips in the systems described below.

[0061] FIG. 9 illustrates an example IR imaging system 900 that includes a sensor chip 904 comprising sensing pixels 910 in accordance with embodiments of the present disclosure. The system 900 includes a package substrate 902, which may be a circuit board (e.g. PCB) for interconnecting the chip 904 with other chips, devices, or components of the overall system 900. The system 900 includes multiple conductive leads 920 that may be used for coupling such otherchips, devices, or components. Each sensing pixel 910 may include a halide lightguide with silver-comprising nanostructures formed by light exposure as described herein.

[0062] In the example shown, the sensing pixels are arranged in a 3D volume of the chip 904 to achieve a desired detection of the incoming wavelengths. Each pixel 910 may include three stacked layers as shown in FIG. 9: a first layer 911 for shortwave IR (SWIR) sensing, a second layer 912 for midwave IR (MWZR) sensing, and a third layer 913 for longwave IR (LWIR) sensing sensing. Each layer may include nanostructures of different sizes corresponding to different parts of the spectrum, which can provide an opportunity to detect multiple spectral bands independently in a single chip configuration. The electrical interconnects of the layers 911-913 are not shown for better understanding the quantum dot configuration. The sensor chip 904 may be mounted on a readout integrated circuit (ROIC) as shown in FIG. 8 to establish a connection with the package substrate 902. The resulting package can then be mounted into standard electronic assemblies, such as larger system-level circuit boards.

[0063] FIG. 10 illustrates another example sensor chip 1002 of the present disclosure. The sensor chip 1002 may be formed in a similar manner as the chip 904 described above, with an array of sensing pixels 1004 where each pixel 1004 includes three layers similar to the layers 911-913 described above. The chip 1002 further includes broadband optical elements 1006, 1008 coupled (e.g., bonded) to certain of the sensing pixels 1004 as shown. The optical elements 1006 coupled to individual ones of the sensing pixels 1004, while the optical element 1008 is coupled to multiple sensing pixels 1004 as shown. Bonding optics directly on the chip 1002 (or onto the chip 904) may minimize reflection surfaces and improve the detection capability of the sensor. The optical elements 1006, 1008 could be a single optical element, multiple optical elements, or an array of optical elements.

[0064] While FIGS. 9 and 10 illustrate a particular number and arrangement of sensing pixels 910, 1004, any number or arrangement of sensing pixels may be contemplated by the present disclosure. In addition, while the examples above describe the use of three layers within each sensing pixel, any suitable number of layers may be used (e.g., 1, 2, or more than 3). In some embodiments, the sensing pixels of FIGS. 9 and 10 could be arranged in a 3D curved configuration that provides minimal distortion of a received image (e.g., due to optical aberrations of the mounted optics), providing improved optical performance. Further, although the layers 911-913 are illustrated as being able to detect particular respective wavelengths in theIR range, the layers 911 -913 may be configured to detect other wavelengths. For example, one of the layers 911-913 (or an additional layer in the stack) may be configured to detect microwaves or other wavelengths of electromagnetic radiation.

[0065] Sub -wavelength plasmonic elements with curved (e.g., mushroom) shape can be fabricated using aspects of the present disclosure for improved absorption and modulation using plasmonic structures.

[0066] In some embodiments, a phase-shifted, chirped volume Bragg grating can be fabricated with aspects of the present disclosure, e.g., via light exposure, with or without thermal treatment and with or without formation of a different plasmonic or crystalline phase.

[0067] In some embodiments, a multi -band infrared imaging device using stacked colloidal quantum dot photodiodes can be fabricated using aspects of the present disclosure by variation of the light exposure and / or thermal processing described above. Methods disclosed herein may substantially simplify a stacking process and reduce fabrication complexity.

[0068] Further, packaging of stacked semiconductor devices and three-dimensional devices with reduced length interconnects for higher transmission bandwidth could be implemented using aspects of the present disclosure. Formation of metal material could be used for implementation of hybrid bonding methods, involving optical material bonding and metal bonding. For example, aspects of the present disclosure can be used for packaging of electronic devices with high density interconnection and integration layer wiring for chiplets, photonics chips, photonics waveguides / packaging and / or other electronics, optical components and package-to-package integration. Aspects of the present disclosure (e.g., a chip as shown in FIG. 9) can also be used to fabricate a light-receiving device that interconnects an electrical circuit board with a fiber ribbon for optical communications.

[0069] Some embodiments may include a high-performance antenna for radio-frequency applications that is formed using metallic phase fabricated between two substrates of the material, such as glass, that serve as means of antenna encapsulation.

[0070] Some embodiments may include an optical device or photodetection system with two dimensional nanophotonic antennas that are fabricated using aspects of the present disclosure to detect the optical signals and make image capturing chips.

[0071] Various aspects have been described above using terms commonly employed by those skilled in the art to convey the substance of their work to others skilled in the art. However,it will be apparent to those skilled in the art that the present disclosure may be practiced with only some of the described aspects. For purposes of explanation, specific numbers, materials, and configurations have been set forth to provide a thorough understanding of the illustrative embodiments. However, it will be apparent to one skilled in the art that aspects of the present disclosure may be practiced without all of the specific details. In addition, well-known features have been omitted or simplified in order not to obscure the illustrative implementations.

[0072] Moreover, it should be understood that the illustrated embodiments are only examples, and should not be taken as limiting the scope of the present invention. For example, steps of disclosed methods may be taken in sequences other than those described, with more, fewer, or other processing steps. The disclosure should not be read as limited to the described order and / or number of steps and / or elements incorporated in the disclosed embodiments unless stated to that effect A person of ordinary skill in the art can readily apply the principles of the present invention to produce more embodiments without deviating from its spirit and scope.

[0073] Terms used herein that are modified by the word “approximately” may include values, arrangements, orientations, spacings, or positions that vary slightly (e.g., + / - 10%) from the meaning of the unmodified term. For example, a light source having a wavelength of approximately 400nm may refer to the light source having a wavelength of between 360-440nm.

[0074] While certain example embodiments have been described above, other embodiments are contemplated by the present disclosure. Some example embodiments are listed below, which may include certain aspects described above. It will be understood that any of the following examples may include any one or more of, and any combination of, the other examples described herein.

[0075] Example Pl is a method comprising: forming an optical waveguide in a host material having broadband infrared (IR) transmission, the waveguide forming comprising forming nano-scale silver structures via laser writing; and tuning a plasmonic resonance of the optical waveguide to a particular wavelength.

[0076] Example P2 includes the method of Example 1, wherein the plasmonic resonance is tuned to a wavelength between approximately 0.5 microns and 25 microns.

[0077] Example P3 includes the method of Example 1 or 2, wherein the host material comprises AgCl / Br.

[0078] Example P4 includes the method of Example 3, wherein the host material further comprises dopants.

[0079] Example P5 includes the method of any one of Examples 1-4, wherein the laser writing is performed with an ultraviolet (UV) laser.

[0080] Example P6 includes the method of any one of Examples 1-5, wherein the tuning is performed by thermal treatment of the waveguide.

[0081] Example P7 is an apparatus or system comprising an optical waveguide as disclosed herein.

[0082] Example P8 is a method of fabricating an optical lightguide as disclosed herein.

[0083] Example P9 includes an apparatus produced by a method disclosed herein.

[0084] Example P10 is a device comprising a chip having a plurality of components arranged in a functional 3D space inside of the chip.

[0085] Example Pl 1 includes the device of Example 10, wherein the components include electrical components.

[0086] Example P12 includes the device of Example 10 or 11, wherein the components include optical components.

[0087] Example P13 includes the device of any one of Examples 10-12, wherein the components are interconnected electrically and optically.

[0088] Example P14 includes the device of any one of Examples 10-13, wherein the components include gratings.

[0089] Example Pl 5 includes the device of Example 14, wherein the gratings are phase shifted Bragg gratings with chirp.

[0090] Example P16 includes the device of any one of Examples 10-15, wherein the components comprise quantum dots produced by light exposure or thermal processing.

[0091] Example 1 is an apparatus comprising: a host material comprising a substantially isotropic halide material composition, wherein an area within the host material comprises nanostructures therein.

[0092] Example 2 includes the apparatus of Example 1, wherein the nanostructures are formed in the host material via light exposure.

[0093] Example 3 includes the apparatus of Example 1 or 2, wherein the nanostructures are laser-written.

[0094] Example 4 includes the apparatus of any one of Examples 1 -3, wherein a size of the nanostructures is below approximately lOOnm.

[0095] Example 5 includes the apparatus of any one of Examples 1-4, wherein the nanostructures comprise a metal.

[0096] Example 6 includes the apparatus of any one of Examples 1-5, wherein a first area within the host material comprising nanostructures is electrically conductive and a second area within the host material comprising nanostructures is optically transmissive.

[0097] Example 7 includes the apparatus of any one of Examples 1-6, wherein the host material defines an optical path, the optical path having an optical transmission of greater than 60% for wavelengths between approximately 0.5um and 25um.

[0098] Example 8 includes the apparatus of Example 7, wherein the optical path comprises an optical element comprising the nanostructures.

[0099] Example 9 includes the apparatus of Example 8, wherein the optical element is one of a Bragg grating, a splitter, a combiner, a resonators, and a multiplexor.

[0100] Example 10 includes the apparatus of any one of Examples 1-9, wherein the halide material composition includes Silver (Ag) and at least one of Chlorine (Cl), Bromine (Br), and Iodine (I).

[0101] Example 11 includes the apparatus of Example 9, wherein the nanostructures comprise Silver (Ag).

[0102] Example 12 includes the apparatus of Example 9, wherein the halide material composition includes AgCl(l-x)Brx, e.g., where x is between approximately 0.4-0.8.

[0103] Example 13 includes the apparatus of any one of Examples 1-12, wherein the halide material composition includes dopants, the dopants including at least one of Cerium (Ce), Erbium (Er), Holmium (Ho), Dysprosium (Dy), Manganese (Mn), Iron (Fe), Chromium (Cr), Thulium (Tm), Ytterbium (Yb), or Neodymium (Nd).

[0104] Example 14 is an optical element comprising: an optical path comprising a substantially isotropic halide material composition; an optical element in the optical path, the optical element defined by nanostructures within the substantially isotropic halide material composition.

[0105] Example 15 includes the optical element of Example 14, wherein the optical element is one of a Bragg grating, a splitter, a combiner, a resonators, and a multiplexor.

[0106] Example 16 includes the optical element of Example 14 or 15, wherein a size of the nanostructures is below approximately lOOnm.

[0107] Example 17 includes the optical element of any one of Examples 14-16, wherein the optical path has an optical transmission of greater than 60% for wavelengths between approximately 0.5um and 25um.

[0108] Example 18 includes the optical element of any one of Examples 14-17, wherein the optical element is defined by an area of the substantially isotropic halide material composition comprising nanostructures.

[0109] Example 19 includes the optical element of any one of Examples 14-17, wherein the optical element is defined by a plurality of areas of the substantially isotropic halide material composition, each area comprising nanostructures.

[0110] Example 20 includes the optical element of any one of Examples 14-19, wherein the halide material composition includes Silver (Ag) and at least one of Chlorine (Cl), Bromine (Br), and Iodine (I), and the nanostructures comprise Silver (Ag).

[0111] Example 21 includes the optical element of any one of Examples 14-20, wherein the halide material composition includes AgCl(l-x)Brx, e.g., where x is between approximately 0.4-0.8, and the nanostructures comprise Ag.

[0112] Example 22 is an optical modulator comprising: the optical element of any one of Examples 14-21; and electrodes on opposite sides of the optical element.

[0113] Example 23 includes the optical modulator of Example 22, further comprising an alternating current (AC) voltage source coupled to the electrodes.

[0114] Example 24 includes the optical modulator of Example 22 or 23, further comprising a direct current (DC) voltage source coupled to the electrodes.

[0115] Example 25 includes the optical modulator of any one of Examples 22-24, wherein the electrodes are co-planar with the optical element.

[0116] Example 26 includes the optical modulator of any one of Examples 22-24, wherein the electrodes are above and below the optical element.

[0117] Example 27 is an optical sensing device, comprising: a readout integrated circuit (ROIC); a plurality of sensing pixels coupled to the ROIC; a layer above the plurality of sensing pixels, the layer comprising nanostructures formed within a substantially isotropic halide material composition.

[0118] Example 28 includes the optical sensing device of Example 27, wherein the layer is a first layer and the device comprises a second layer comprising nanostructures formed within a substantially isotropic halide material composition, the second layer above the first layer.

[0119] Example 29 includes the optical sensing device of Example 28, wherein the sensing pixels are first sensing pixels, and the device further comprises a plurality of second sensing pixels between the first layer and the second layer.

[0120] Example 30 includes the optical sensing device of Example 28, wherein the first layer is configured to detect light of a first wavelength and the second layer is configured to detect light of a second wavelength.

[0121] Example 31 includes the optical sensing device of any one of Examples 28-30, further comprising an interconnect package substrate, the ROIC coupled to the interconnect package substrate.

[0122] Example 32 is a method of forming an optical element, comprising: depositing a molten halide material into a retaining element; and cooling the retaining element and the molten halide material to solidify the halide material; and forming nanostructures within an area of the solidified halide material by exposing the area to light.

[0123] Example 33 includes the method of Example 32, wherein exposing the area of the solidified halide material to light comprises focusing a laser onto the area for a duration of time.

[0124] Example 34 includes the method of Example 33, wherein a wavelength of the laser is approximately 400 nm.

[0125] Example 35 includes the method of any one of Examples 32-34, further comprising heating the solidified halide material after exposing the area of the solidified halide material to light.

[0126] Example 36 includes the method of any one of Examples 32-35, wherein the halide material is solidified in a microgravity environment.

[0127] Example 37 is an optical element formed by the method of Examples 32-36.

[0128] Example 38 includes the optical element of Example 37, wherein the optical element has an optical transmission of greater than 60% for wavelengths between approximately 0.5um and 25um.

[0129] Example 39 includes the optical element of Example 37 or 38, wherein the optical element comprises one of a Bragg grating, a splitter, a combiner, a resonators, and a multiplexor formed by the nanostructures.

Claims

CLAIMS1. An apparatus comprising: a host material comprising a substantially isotropic halide material composition, wherein an area within the host material comprises nanostructures therein.

2. The apparatus of claim 1, wherein the nanostructures are formed in the host material via light exposure.

3. The apparatus of claim 1 or 2, wherein the nanostructures are laser-written.

4. The apparatus of any one of claims 1-3, wherein a size of the nanostructures is below approximately lOOnm.

5. The apparatus of any one of claims 1-4, wherein the nanostructures comprise a metal.

6. The apparatus of any one of claims 1-5, wherein a first area within the host material comprising nanostructures is electrically conductive and a second area within the host material comprising nanostructures is optically transmissive.

7. The apparatus of any one of claims 1-6, wherein the host material defines an optical path, the optical path having an optical transmission of greater than 60% for wavelengths between approximately 0.5um and 25um.

8. The apparatus of claim 7, wherein the optical path comprises an optical element comprising the nanostructures.

9. The apparatus of claim 8, wherein the optical element is one of a Bragg grating, a splitter, a combiner, a resonators, and a multiplexor.

10. The apparatus of any one of claims 1-9, wherein the halide material composition includes Silver (Ag) and at least one of Chlorine (Cl), Bromine (Br), and Iodine (I).

11. The apparatus of claim 9, wherein the nanostructures comprise Silver (Ag).

12. The apparatus of claim 9, wherein the halide material composition includes AgCl(i-X)Brx, e.g., where x is between approximately 0.4-0.8.

13. The apparatus of any one of claims 1-12, wherein the halide material composition includes dopants, the dopants including at least one of Cerium (Ce), Erbium (Er), Holmium (Ho), Dysprosium (Dy), Manganese (Mn), Iron (Fe), Chromium (Cr), Thulium (Tm), Ytterbium (Yb), or Neodymium (Nd).

14. An optical element comprising: an optical path comprising a substantially isotropic halide material composition; an optical element in the optical path, the optical element defined by nanostructures within the substantially isotropic halide material composition.

15. The optical element of claim 14, wherein the optical element is one of a Bragg grating, a splitter, a combiner, a resonators, and a multiplexor.

16. The optical element of claim 14 or 15, wherein a size of the nanostructures is below approximately lOOnm.

17. The optical element of any one of claims 14-16, wherein the optical path has an optical transmission of greater than 60% for wavelengths between approximately 0.5um and 25um.

18. The optical element of any one of claims 14-17, wherein the optical element is defined by an area of the substantially isotropic halide material composition comprising nanostructures.

19. The optical element of any one of claims 14-17, wherein the optical element is defined by a plurality of areas of the substantially isotropic halide material composition, each area comprising nanostructures.

20. The optical element of any one of claims 14-19, wherein the halide material composition includes Silver (Ag) and at least one of Chlorine (Cl), Bromine (Br), and Iodine (I), and the nanostructures comprise Silver (Ag).

21. The optical element of any one of claims 14-20, wherein the halide material composition includes AgCl(i-X)Brx, e.g., where x is between approximately 0.4-0.8, and the nanostructures comprise Ag.

22. An optical modulator comprising: the optical element of any one of claims 14-21; and electrodes on opposite sides of the optical element.

23. The optical modulator of claim 22, further comprising an alternating current (AC) voltage source coupled to the electrodes.

24. The optical modulator of claim 22 or 23, further comprising a direct current (DC) voltage source coupled to the electrodes.

25. The optical modulator of any one of claims 22-24, wherein the electrodes are coplanar with the optical element.

26. The optical modulator of any one of claims 22-24, wherein the electrodes are above and below the optical element.

27. An optical sensing device, comprising: a readout integrated circuit (ROIC); a plurality of sensing pixels coupled to the ROIC; a layer above the plurality of sensing pixels, the layer comprising nanostructures formed within a substantially isotropic halide material composition.

28. The optical sensing device of claim 27, wherein the layer is a first layer and the device comprises a second layer comprising nanostructures formed within a substantially isotropic halide material composition, the second layer above the first layer.

29. The optical sensing device of claim 28, wherein the sensing pixels are first sensing pixels, and the device further comprises a plurality of second sensing pixels between the first layer and the second layer.

30. The optical sensing device of claim 28, wherein the first layer is configured to detect light of a first wavelength and the second layer is configured to detect light of a second wavelength.

31. The optical sensing device of any one of claims 28-30, further comprising an interconnect package substrate, the ROIC coupled to the interconnect package substrate.

32. A method of forming an optical element, comprising: depositing a molten halide material into a retaining element; and cooling the retaining element and the molten halide material to solidify the halide material; and forming nanostructures within an area of the solidified halide material by exposing the area to light.

33. The method of claim 32, wherein exposing the area of the solidified halide material to light comprises focusing a laser onto the area for a duration of time.

34. The method of claim 33, wherein a wavelength of the laser is approximately 400 nm.

35. The method of any one of claims 32-34, further comprising heating the solidified halide material after exposing the area of the solidified halide material to light.

36. The method of any one of claims 32-35, wherein the halide material is solidified in a microgravity environment.

37. An optical element formed by the method of claims 32-36.

38. The optical element of claim 37, wherein the optical element has an optical transmission of greater than 60% for wavelengths between approximately 0.5um and 25um.

39. The optical element of claim 37 or 38, wherein the optical element comprises one of a Bragg grating, a splitter, a combiner, a resonators, and a multiplexor formed by the nanostructures.

Images