This paper describes a resolution improvement for a mercury cadmium telluride (MCT) infrared charge-coupled device (IRCCD) using a new microscanner. To keep the microscanner compact, the scanner prism is placed between the lens and the IRCCD, and driven by a bimorph piezoelectric actuator. By compensating the drive pulse and optimizing the prism thickness, the microscanner gives a fast and stable response with low distortion. The medium wavelength imager developed for the microscanner gives a 128 X 128 pixel thermal image in the 3 to 5 micrometers band using a 64 X 64 element IRCCD. The Nyquist frequency was increased from 10 to 20 cycles/mm to reduce aliasing without decreasing the S/N ratio. The noise equivalent temperature difference (NETD) was measured at 0.06 K with an f-1.7 lens. The modulation transfer function (MTF) was estimated by considering the scan distortion and the pixel aperture profile. By optimizing the aperture profile of the photodiode, the MTF at the Nyquist frequency was increased from 0 to 20%.

Date Published: 1 September 1992
PDF: 8 pages
Proc. SPIE 1685, Infrared Detectors and Focal Plane Arrays II, (1 September 1992); doi: 10.1117/12.137814

Published in SPIE Proceedings Vol. 1685:
Infrared Detectors and Focal Plane Arrays II
Eustace L. Dereniak; Robert E. Sampson, Editor(s)