Design and fabrication of a polymer gradient-index optical element for a high-performance eyepiece

Visconti, Anthony J.; Fang, Kejia; Corsetti, James A.; McCarthy, Peter W.; Schmidt, Greg; Moore, Duncan T.

doi:10.1117/1.oe.52.11.112107

Cited by 19 publications

(12 citation statements)

References 9 publications

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“…Gradient refractive index (GRIN) materials are ideal for optical elements where a gradual variation in the refractive index is used to manipulate light . This continuous variation in index not only allows an additional degree of freedom that can be used for high focusing power or aberration correction, but also provides unique and tailorable dispersion characteristics not possible with homogenous optical materials . Implementation of GRIN optical designs can enable cost effectiveness through the manufacturing of fewer optical elements but more importantly, reduces the number of coated surfaces and reflections while improving transmission and spectral range performance.…”

Section: Introductionmentioning

confidence: 99%

Melt property variation in GeSe₂‐As₂Se₃‐PbSe glass ceramics for infrared gradient refractive index (GRIN) applications

Yadav

Buff

Kang

et al. 2018

Int J of Appl Glass Sci

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Melt size‐dependent physical property variation is examined in a multicomponent GeSe2‐As2Se3‐PbSe chalcogenide glass developed for gradient refractive index applications. The impact of melting conditions on small (40 g) prototype laboratory‐scale melts extended to commercially‐relevant melt sizes (1.325 kg) have been studied and the role of thermal history variation on physical and optical property evolution in parent glass, the glass’ crystallization behavior and postheat‐treated glass ceramics, is quantified. As‐melted glass morphology, optical homogeneity and heat treatment‐induced microstructure following a fixed, two‐step nucleation and growth protocol exhibit marked variation with melt size. These attributes are shown to impact crystallization behavior (growth rates, resulting crystalline phase formation) and induced effective refractive index change, neff, in the resulting optical nanocomposite. The magnitude of these changes is discussed based on thermal history related melt conditions.

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Section: Introductionmentioning

confidence: 99%

Melt property variation in GeSe₂‐As₂Se₃‐PbSe glass ceramics for infrared gradient refractive index (GRIN) applications

Yadav

Buff

Kang

et al. 2018

Int J of Appl Glass Sci

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“…The following design analysis extends previous work using spherical gradient-index optical elements in the design of high-performance eyepieces 3,4 , and demonstrates the effective use of a measured thermoformed PMMA/PS copolymer GRIN lens in an all-plastic high-performance eyepiece design.…”

Section: Introductionmentioning

confidence: 89%

“…In fact, during optimization of the GRIN eyepiece, physical constraints are imposed on the GRIN element so that the lens fits within the compressed lens blank. The first surface of the GRIN lens becomes nearly plano during optimization; subsequently, this surface is set to be plano in order to simplify the fabrication procedure of the GRIN element 4 . The GRIN lens has a total index of refraction change of 0.024 at λ = 587 nm.…”

Section: Eyepiece Designsmentioning

confidence: 99%

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All-plastic high-performance eyepiece design utilizing a spherical gradient-index lens

Visconti¹,

Fang²,

Schmidt³

et al. 2014

SPIE Proceedings

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“…GRIN 2 (lens element 6) was a combination of IRG22/IRG23. Other efforts in GRIN design have focused on the reduction of lens count and weight 10 . This effort was focused on the improvement of narcissus withput the loss of performance in a challenging design.…”

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confidence: 99%

Reducing narcissus with a GRIN

Vizgaitis

Hastings

2015

SPIE Proceedings

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Narcissus is caused by the reflection of the cold stop off a lens surface back to the image plane of a cooled infrared system and can be very difficult to remove from a lens design perspective. New infrared GRIN materials show the ability to reduce the amount of narcissus in an optical system without the reduction in performance or addition of optical elements. BACKGROUNDIn a typical workflow for an infrared optical design a significant amount of effort is spent defining the requirements and developing a design that meets those requirements followed by refining the design concept with realistic tolerances. At this point the design is at state where the designer can examine the effects of narcissus which typically reveal one or more surfaces that contribute an unacceptable amount of narcissus to the system. In a scanned system, this can be disastrous because the narcissus may not be removable. The impact on a system with a staring focal plane array (FPA) is usually less severe 1 . The narcissus can temporarily be mitigated by non-uniformity correction (NUC), but this is highly dependent on the location of the element that causes the problem. Narcissus is caused by the reflection of the image of the cold stop back to the image plane from individual lens surfaces 2 . All refractive thermal systems have some amount of narcissus as each optical surface provides a reflection path back to the image plane. Each surface provides a reflection back to the image plane. The level of narcissus from each surface is dependent on the strength of the image that is formed of the cold space back to the FPA. This is a function of both the optical design and the coatings that are applied to the individual surfaces.Narcissus manifests itself in two different methods. The first form is uniformly distributed across the FPA and affects the background level of the sensor. This does degrade the performance of the system by introducing an additional noise source, but after processing corrections and adjusting gain, level, and contrast, it is general imperceptible to the user. It can impact the dynamic range of the system, so it cannot be completely ignored. The second form of narcissus, and more impactful, is non-uniformly distributed across the FPA and limits the performance of the sensor. This non-uniform narcissus is observed in the image from Figure 1 where there appears to be a dark circle forming in the middle of the image. This dark circle is the image of the cold stop as well as the warm space that surrounds it. The large contrast in signal is due to the large delta in temperature from the cold space to the warm space (delta T = 220K for a system at 300K and the detector at 80K). In both cases, changes to the system such as temperature, FPA drift, focus, etc. can cause the narcissus to reappear as conditions deviate from the state that the NUC was performed. Figure 1: Thermal image with strong narcissus contribution 3 .

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Design and fabrication of a polymer gradient-index optical element for a high-performance eyepiece

Cited by 19 publications

References 9 publications

Melt property variation in GeSe₂‐As₂Se₃‐PbSe glass ceramics for infrared gradient refractive index (GRIN) applications

Melt property variation in GeSe₂‐As₂Se₃‐PbSe glass ceramics for infrared gradient refractive index (GRIN) applications

All-plastic high-performance eyepiece design utilizing a spherical gradient-index lens

Reducing narcissus with a GRIN

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Design and fabrication of a polymer gradient-index optical element for a high-performance eyepiece

Cited by 19 publications

References 9 publications

Melt property variation in GeSe2‐As2Se3‐PbSe glass ceramics for infrared gradient refractive index (GRIN) applications

Melt property variation in GeSe2‐As2Se3‐PbSe glass ceramics for infrared gradient refractive index (GRIN) applications

All-plastic high-performance eyepiece design utilizing a spherical gradient-index lens

Reducing narcissus with a GRIN

Contact Info

Product

Resources

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Melt property variation in GeSe₂‐As₂Se₃‐PbSe glass ceramics for infrared gradient refractive index (GRIN) applications

Melt property variation in GeSe₂‐As₂Se₃‐PbSe glass ceramics for infrared gradient refractive index (GRIN) applications