A new, monolithic encoding digital photodetecter array

Abstract

At present, each element of the photodetecter array (PDA) is an individual source providing electronic signal, it must be connected with a seperate signal amplifying circuits. The more the array elements are, the more complex the circuits are. Another problem is that this kind of PDA has a high false-code-rate. We have designed and manufactured a new monolithic encoding digital PDA adopting the Gray encoding mode which has low false-code- rate. It is made of 32 photodiodes on one silicon chip. All 32 photodiodes is divided into six groups according a certain pattern, then connected to six output points followed by six groups of hybrid integrated amplifieres where the electronic signal is amplified and out put a 6-bit binary digit according Gray code. They are all mounted in a single sealed package. If the design is changed, similar encoding digital photodetecter array can also out put other bits binary code. Some measurement results is presented.