A novel binarily detectable high-speed optical position-sensitive device (BPSD)

A binary position sensitive device (BPSD) which can be used to detect the position of optical illumination in the binary form is described. This device consists of a p-i-n structure, sandwiched with two-axis (x and y) stripelike electrodes. For preliminary laboratory demonstration, a test device with an active area of 1 cm/sup 2/ including 8*8 elements was fabricated using an a-SiC:H single heterostructure. The fabricated device showed a high-speed response of 0.3 mu s for the pulsive input illumination and high quantum efficiency over more than unity having a dark current of 10 pA/element. Output signal uniformity was +or-5%, which is suitable for digital applications. In this demonstration, it was found that the response limitation depends on the computer processing time.<
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