Abstract
We show the feasibility of two new programmable diffractive optical elements (DOE). On one hand, we demonstrate the realization of programmable apodizers. With the term apodizer we refer to non-uniform amplitude filters used to modify the point-spread function (PSF) of an optical system. On the other hand, we show the simultaneous realization of a Fresnel lens and an amplitude filter in a single DOE: The programmable amplitude apodized Fresnel (PAAFL). Two different modulation regimes are required to generate these DOEs: amplitude-only regime for the programmable apodizer and phase-only regime for the PAAFL. We show that a twisted-nematic liquid crystal spatial light modulator (TN-LCSLM) inserted between two wave plates and two polarizers is able to provide both modulation regimes. Different types of amplitude filters, such as axial hyperresolving, transverse apodizing and transverse hyperresolving have been implemented both as programmable apodizers and as PAAFLs. We provide experimental results for the performance of the two new DOEs. The agreement with the numerical results is excellent, thus demonstrating the feasibility of our proposal.
Original language | English |
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Pages (from-to) | 99-110 |
Journal | Proceedings of SPIE - The International Society for Optical Engineering |
Volume | 4457 |
DOIs | |
Publication status | Published - 1 Jan 2001 |
Keywords
- Amplitude apodized Fresnel lens
- Amplitude-only modulation
- Diffractive optical elements
- Fresnel lens
- Inherent equivalent apodizing effect
- Liquid crystal display
- Phase-only modulation
- Programmable apodizer
- Spatial light modulator
- Twisted nematic