18 December 2012 Diffraction grating-based optical readout for thermal imaging
Author Affiliations +
The thermal sensor system presented in this paper is based on the mechanical bending due to the incident IR radiation. A diffraction grating is embedded under each pixel to facilitate optical readout. Typically the first diffraction order is used to monitor the sub-micron mechanical displacement with sub-nanometer precision. In this work; two different optical readout systems based on diffraction gratings are analyzed. First setup employs a conventional 4f optical system. In this one-to-one imaging system, collimated light is propagated through a lens, filtered with an aperture and then imaged onto a CCD by a second lens. Second system is more compact to improve image quality and to reduce noise. This is achieved by using an off-axis converging laser beam illumination that forms the Fourier plane near the imaging lens. This approach has important advantages such as reducing number of optical components and minimizing the optical path. The system was optimized considering parameters such as laser converging angle, laser beam size at MEMS chip, and magnification of the imaging system.
© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Ulas Adiyan, Ulas Adiyan, R. Burak Erarslan, R. Burak Erarslan, Onur Ferhanoglu, Onur Ferhanoglu, Hamdi Torun, Hamdi Torun, Hakan Urey, Hakan Urey, } "Diffraction grating-based optical readout for thermal imaging", Proc. SPIE 8550, Optical Systems Design 2012, 855026 (18 December 2012); doi: 10.1117/12.981443; https://doi.org/10.1117/12.981443

Back to Top