4x4數位矽光電倍增器之測距儀應用

Abstract

在此論文中，我們使用台積電0.18m高壓標準CMOS製程製作的單光子崩潰二極體元件，搭配所設計的被動放電電路，利用藉由工研院所下線的4x4矽光電倍增器與PicoQuant公司所生產的時間解析單光子計數系統完成一個簡易的測距儀，再將測量結果加以演算法處理，並將結果作更一步整理分析，並比較背景光強弱對精準度上的影響，再利用FPGA作同步偵測(coincidence)去改善背景光較強時所會產生的誤差。我們的測距儀在低能量雷射400µW、時間1ms完成測量25公尺的實際應用，且其誤差最大距離小於10公分，單一距離標準差為1.25公分，並在2.4公尺應證了抑制背景光的方法，SPAD受強背景光照射接近於飽和狀態(單一像素電路速率為8.2MHz)但在短積分時間1ms依然能夠在標準差為1cm的狀態下辨別去2.4公尺距離，藉由這些結果，我們了解到SPAD測距儀在弱光應用上是未來一個具有潛力的發展方向。

In this work, we realize a 4x4 silicon photonmultiplier with single photon avalanche diodes (SPADs) and passive quenching circuit by using TSMC HV0.18m standard CMOS technology.The 4x4 silicon photonmultiplier taped-out through ITRI is used to do distance measurement with PicoQuant's Time-Correlated Single Photon Counting system and then the result is processed by algorithm. The result is further analyzed and then compare with the effect of different background light intensity on accuracy.To improve the error of strong background light casued used FPGA to do coincidence detection. Our rangefinder is used to measure 25 meters at low energy 400mW laser in 1ms. The error of maximum is less than 10cm.The standard deviation at 25 meter is 1.25cm.And it is successful to test method of background suppression at 2.4 meter. The SPAD is close to satuation condition(Single pixel circuit at rate of 8.2MHz) at strong background light but the distance of 2.4 meters in the standard deviation of 1cm is still distinguished by rangefinder at short integration time of 1ms.According to the results,We realize that SPAD rangefinder have great potential direction of development in weak light application for future research.