Karlsson C J, Olsson F A
Department of Laser Systems, Defence Research Establishment, PO Box 1165, S-581 11 Linkoping, Sweden.
Appl Opt. 1999 May 20;38(15):3376-86. doi: 10.1364/ao.38.003376.
The performance of a frequency-modulated continuous-wave (FMCW) semiconductor laser radar has been examined. Frequency modulation (linear chirp) has been studied experimentally in detail. To create a linear frequency sweep, we modified the modulating function according to the measured frequency response of the laser, using an arbitrary function generator. The measurements indicate the possibility of achieving a spectral width of the signal peak that is transform limited rather than limited by the frequency modulation response of the laser, which permits the use of a narrow detection bandwidth. The narrow width results in a relatively high signal-to-noise ratio for low output power and thus also in relatively long-range and high-range accuracy. We have performed measurements of a diffuse target to determine the performance of a test laser radar system. The maximum range, range accuracy, and speed accuracy for a semiconductor laser with an output power of 10 mW and a linewidth of 400 kHz are presented. The influence of the laser's output power and coherence length on the performance of a semiconductor-laser-based FMCW laser radar is discussed.
对调频连续波（FMCW）半导体激光雷达的性能进行了研究。对频率调制（线性啁啾）进行了详细的实验研究。为了产生线性频率扫描，我们根据激光器的测量频率响应，使用任意函数发生器修改了调制函数。测量结果表明，有可能实现信号峰值的光谱宽度，该宽度受变换限制而非激光器的频率调制响应限制，这允许使用窄检测带宽。窄宽度导致低输出功率下具有相对较高的信噪比，从而也具有相对较远的探测距离和较高的距离精度。我们对漫反射目标进行了测量，以确定测试激光雷达系统的性能。给出了输出功率为10 mW、线宽为400 kHz的半导体激光器的最大探测距离、距离精度和速度精度。讨论了激光器的输出功率和相干长度对基于半导体激光器的FMCW激光雷达性能的影响。
