GRIN optics for multispectral infrared imaging

Gibson, Dan; Bayya, Shyam; Nguyen, Vinh; Sanghera, J.S.; Kotov, Mikhail; Drake, Gryphon

doi:10.1117/12.2177136

Cited by 17 publications

(23 citation statements)

References 6 publications

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“…The production of devices that can combine visible and LWIR imaging in a single solution is currently the main technological challenge [5]. The products currently commercialized rely on two separate combination of optical components to capture signals from both visible and LWIR.…”

Section: Introductionmentioning

confidence: 99%

Ga-La-S-Se glass for visible and thermal imaging

Ravagli

Craig

Lincoln

et al. 2017

Advanced Optical Technologies

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Chalcogenide glasses are emerging as important enabling materials for low-cost infrared imaging by virtue of their transparency in the key short-wave infrared (SWIR) to long-wave infrared (LWIR) bands and the ability to be mass produced and molded into near-net shape lenses. In this paper, we introduce a new family of chalcogenide glasses, which offer visible as well as infrared transmission and improved thermal and mechanical properties. These glasses are based on Ga 2 S 3 -La 2 S 3 with added Ga 2 Se 3 -up to complete the substitution of Ga 2 S 3 for Ga 2 Se 3 . The samples are prepared via the melt-quench method in an argon-purged atmosphere. All the studied compositions showed a lower glass transition temperature and an extended transmission window. Particularly, the LWIR transmission was extended from about 9 μm for gallium lanthanum sulfide (Ga-La-S) glass to about 15 μm for Se-added Ga-La-S retaining visible transmission from around 463 nm. The thermal and mechanical properties were investigated to prove the suitability of these novel materials for the production of optical components such as visible to LWIR lenses. Their suitability for drawing into optical fibers is also discussed.

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Section: Introductionmentioning

confidence: 99%

Ga-La-S-Se glass for visible and thermal imaging

Ravagli

Craig

Lincoln

et al. 2017

Advanced Optical Technologies

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“…Gradient refractive index (GRIN) optics present unique opportunities for control of the chromatic properties of an optical system . Novel GRIN materials can be engineered to provide dispersive properties which lie far outside those found in nature, providing new degrees of freedom for optical design as well as the potential for use in new applications . In this paper, a novel photothermal process is utilized to spatially modulate high‐index nanocrystals within a metastable chalcogenide glass thin film, composed of Ge‐As‐Pb‐Se (GAP‐Se) constituents, thereby achieving ultralow dispersion over an unprecedented bandwidth of 1–12 µm wavelength and enabling creation of an arbitrary index gradient required for GRIN optics.…”

Section: The Calculation Of Vhomo and Vgrin For Gap‐se Glasses Based mentioning

confidence: 99%

“…By taking advantage of the additional degrees of freedom associated with volumetric focusing, it is possible to engineer a material system capable of dispersive properties that lie far outside what is found in nature, such as ultralow dispersion across a broadband spectrum, thereby greatly reducing chromatic aberration . GRIN materials are media in which the refractive index is varied as a function of spatial position, usually through a variation of material composition . This variation can be induced by chemical diffusion (i.e., ion exchange), lamination of homogeneous, dissimilar materials (as in the case of polymers or glasses), and ion implantation to yield either radial or axial GRIN, respectively.…”

Section: The Calculation Of Vhomo and Vgrin For Gap‐se Glasses Based mentioning

confidence: 99%

“…GRIN materials are media in which the refractive index is varied as a function of spatial position, usually through a variation of material composition . This variation can be induced by chemical diffusion (i.e., ion exchange), lamination of homogeneous, dissimilar materials (as in the case of polymers or glasses), and ion implantation to yield either radial or axial GRIN, respectively. Recently, a micropoling method has been shown to enable both lateral and axial refractive index modification with exceptional long‐term stability within a near surface (<10 µm) layer in a bulk multicomponent chalcogenide glass .…”

Section: The Calculation Of Vhomo and Vgrin For Gap‐se Glasses Based mentioning

confidence: 99%

“…The 14%GeSe 2 –42%As 2 Se 3 –44%PbSe GAP‐Se film composition was selectively engineered to modulate the concentration of high‐index nanocrystals, thereby providing ultralow dispersion across the entire 1–12 µm broadband spectrum. The Abbé number at a corresponding spectral range for a homogeneous media and a radial GRIN lens be respectively defined as V homo = ( n middle − 1)/( n short − n long ) and V GRIN = (Δ n middle )/(Δ n short − Δ n long ) where n is the refractive index and ∆ n is the change in refractive index for the material system at the corresponding positions within the chosen spectrum . To determine the chromatic performance of the GAP‐Se glass, we tested a series of films exposed to varying doses from 5.05 × 10 2 to 1.51 × 10 4 J cm −2 , which had been thermally treated for 30 min at 190 °C (Figure d).…”

Section: The Calculation Of Vhomo and Vgrin For Gap‐se Glasses Based mentioning

confidence: 99%

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Ultralow Dispersion Multicomponent Thin‐Film Chalcogenide Glass for Broadband Gradient‐Index Optics

et al. 2018

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A novel photothermal process to spatially modulate the concentration of sub-wavelength, high-index nanocrystals in a multicomponent Ge-As-Pb-Se chalcogenide glass thin film resulting in an optically functional infrared grating is demonstrated. The process results in the formation of an optical nanocomposite possessing ultralow dispersion over unprecedented bandwidth. The spatially tailored index and dispersion modification enables creation of arbitrary refractive index gradients. Sub-bandgap laser exposure generates a Pb-rich amorphous phase transforming on heat treatment to high-index crystal phases. Spatially varying nanocrystal density is controlled by laser dose and is correlated to index change, yielding local index modification to ≈+0.1 in the mid-infrared.

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Infrared Glass–Ceramics with Multidispersion and Gradient Refractive Index Attributes

Sisken

Kang

Veras

et al. 2019

Adv Funct Materials

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Infrared (IR) glass-ceramics (GCs) hold the potential to dramatically expand the range of optical material solutions available for use in bulk and planar optical systems in the IR. Current material solutions are limited to single-or polycrystalline materials and traditional IR-transparent optical glasses. GCs that can be processed with spatial control and extent of induced crystallization present the opportunity to realize an effective refractive index variation, enabling arbitrary gradient refractive index elements with tailored optical function. This work discusses the role of the parent glass composition and morphology on nanocrystal phase formation in a multicomponent chalcogenide glass. Through a two-step heat treatment protocol, a Ge-As-Pb-Se glass is converted to an optical nanocomposite where the type, volume fraction, and refractive index of the precipitated crystalline phase(s) define the resulting nanocomposite's optical properties. This modification results in a giant variation in infrared Abbe number, the magnitude of which can be tuned with control of crystal phase formation. The impact of these attributes on the GCs' refractive index, transmission, dispersion, and thermo-optic coefficient is discussed. A systematic protocol for engineering homogeneous or gradient changes in optical function is presented and validated through experimental demonstration employing this understanding.

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GRIN optics for multispectral infrared imaging

Cited by 17 publications

References 6 publications

Ga-La-S-Se glass for visible and thermal imaging

Ga-La-S-Se glass for visible and thermal imaging

Ultralow Dispersion Multicomponent Thin‐Film Chalcogenide Glass for Broadband Gradient‐Index Optics

Infrared Glass–Ceramics with Multidispersion and Gradient Refractive Index Attributes

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