Use of diffractive elements to improve IR optical systems

Nevo, Yitzhak; Nir, D.; Wachtel, Sylvie

doi:10.1117/12.452238

Cited by 3 publications

(2 citation statements)

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“…Hence, during the design process of a cooled IR optical system, narcissus phenomenon has to be considered. 11 Typically, YNI value is used to characterize the amount of narcissus, where Y is the incident height of paraxial rays on one optical surface, N is the refractive index of one optical material, and I is the incident angle of marginal rays at one optical surface. If the YNI value is greater than 1, it indicates that the impact of narcissus to the optical system can be ignored.…”

Section: Narcissus Analysismentioning

confidence: 99%

Optical system design of four-channel dual-band infrared panoramic imaging

2019

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In order to reduce the volume of a panoramic optical system, a four-channel infrared dual-band panoramic imager was designed using spatial multicamera image mosaicking. Each optical system of the imaging channel was designed in a double imaging configuration with an F-number of 2, working bands of MWIR 3 to 5 μm and LWIR 8 to 12 μm, and a full field of view (FOV) of 122 deg. By adopting refractive-diffractive hybrid optical elements and introducing aspheric designs, the system was made to achieve temperature compensation from −40°C to 60°C by means of optical passive athermalization. Results indicate that the system attained almost 100% cold stop efficiency. At the Nyquist frequency of 18 lp/mm, the modulation-transfer-function (MTF) of the MWIR system was higher than 0.70 at the edges of the FOV, whereas the MTF of LWIR system was greater than 0.35 for the same condition, both approaching the diffraction limit.

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Section: Narcissus Analysismentioning

confidence: 99%

Optical system design of four-channel dual-band infrared panoramic imaging

2019

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“…[3][4][5] de la Fuente 6 shows that by using the IR material GASIR1, one can reduce the chromatic aberration of dual-band midwave infrared (MWIR) and long-wave infrared (LWIR) optics. Snyder and Vizgaitis 1 and Sinclair and Dobrowolski 2 use mirrors optics to avoid chromatic aberrations.…”

Section: Introductionmentioning

confidence: 99%

Dual-band optics

Nevo¹

2013

Opt. Eng

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A dual-band optics design for disjoint spectral bands and for a cooled FPA sensor, sensitive to both bands, is presented. The use of special optical splitting mechanisms enables matching the optical paths of both bands to the same sensor. Reasonable optical performance and good registration were achieved for dual bands such as 8 to 12 μm together with 3.6 to 4.2 μm, and for the 3.6 to 4.2 μm band with various monochromatic laser bands in the 1.06 to 1.8 μm spectral range. Regular IR materials were used with aspheric and diffractive surfaces. Both singleobjective designs and zoomed-objective designs are presented.

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