Pyroelectric Surface Acoustic Wave Scanned Imager Analysis and Testing.

摘要

This report covers information on pyroelectric imaging using SAW scanning. The results are applicable to other methods of image scanning as well. The possibility of using surface acoustic waves (SAWs) to scan optical images on semiconductors has been demonstrated. In order to do the analogous scanning of images in the infrared portion of the spectrum one has to cool the semiconductor to about 100 K. This increases initial system cost, decreases shelf life span, and requires additional servicing when operationally deployed. One method of circumventing the cooling problem is to use the pyroelectrical effect for the infrared light sensing mechanism. When heated by incident radiation a pyroelectric develops a polarization surface charge. This polarization surface charge can exert an electric field on an adjacent semiconductor and change the charge distribution at its surface. If two SAWs in the pyroelectric interact nonlinearly with the varying surface charge in the semiconductor, then one can read out an image by observing the current versus time across the semiconductor.