Experimental verification of the minimum number of diffractive zones for effective chromatic correction in the LWIR
| Autor: | Ken F. Walsh, J. L. Ramsey, M. Smith, John Deegan |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Physics
Kinoform business.industry 02 engineering and technology 01 natural sciences Computer-generated holography law.invention 010309 optics Lens (optics) 020210 optoelectronics & photonics Optics Apochromat law 0103 physical sciences Chromatic aberration 0202 electrical engineering electronic engineering information engineering Focal length Chromatic scale Spatial frequency business |
| Zdroj: | SPIE Proceedings. |
| ISSN: | 0277-786X |
| DOI: | 10.1117/12.2223755 |
| Popis: | With the move to smaller pixel sizes in the longwave IR region there has been a push for shorter focal length lenses that are smaller, cheaper and lighter and that resolve lower spatial frequencies. As a result lenses must have better correction for both chromatic and monochromatic aberrations. This leads to the increased use of aspheres and diffractive optical elements (kinoforms). With recent developments in the molding of chalcogenide materials these aspheres and kinoforms are more cost effective to manufacture. Without kinoforms the axial color can be on the order of 15 μm which degrades the performance of the lens at the Nyquist frequency. The kinoforms are now on smaller elements and are correcting chromatic aberration which is on the order of the design wavelength. This leads to kinoform structures that do not require large phase changes and therefore have 1.5 to just over 2 zones. The question becomes how many zones are required to correct small amounts of chromatic aberration in the system and are they functioning as predicted by the lens design software? We investigate both the design performance and the as-built performance of two designs that incorporate kinoforms for the correction of axial chromatic aberration. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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