白天单光子探测激光测距

单光子探测激光测距是实现远距离高精度测距的一种重要方法。由于白天的背景噪声约为夜晚的100万倍,传统的单光子探测器白天极易饱和甚至损坏,单光子探测激光测距在白光背景噪声环境中非常难识别微弱的回波信号。本文发展了一种基于FP标准具滤光的单光子探测激光测距装置,采用532 nm窄带干涉滤光片和线宽为10 pm的FP标准具进行二级滤光,并且通过压电旋转台驱动FP标准具,使其中心波长与激光波长锁定,保持最大的透过率。该测距装置有效地降低了白光背景噪声,采用PMT单光子探测器,在532 nm波段实现了白天单光子探测激光测距。在实验中,阳光照度为1.1×10~4 lx时,背景光噪声计数被抑制到900 kcps,探测距离为1.4 km时,信噪比可达16 dB。

Daytime Single-photon Detection Laser Ranging

Single-photon detection laser ranging is an important method to achieve long distance and high precision ranging.The single-photon detector is easy to be saturated or even damaged in the daytime,and it is very difficult to identify the weak echo signal in the white light background,because the daytime background is about 1 million times of that at night.In this paper,a daytime single-photon detection laser rangefinder was developed.A two-stage filtering were used with a narrow-band interference filter and a FP etalon with a line width of 10 pm.The FP etalon was driven by a piezoelectric deflector to keep the center wavelength in line with the laser wavelength,so as to maintain the maximum transmission of the echo photons.The system could reduce the white light background noise effectively,and realized single-photon detection laser ranging with a PMT single photon detector at 532 nm in the daytime.In the experiment,the background noise was suppressed to 9×10^5 counts per second when the sunlight illuminance was 1.1×10^4 lx.The single-photon detection laser ranging was realized with a distance of 1.4 km and the signal-to-noise ratio was 16 dB.