Zhang Gong, Ding Zhihuan, Wang Kuankuan, Jiang Chun, Lou Jiajun, Lu Qiaoyin, Guo Weihua
Opt Express. 2022 Jan 17;30(2):2599-2609. doi: 10.1364/OE.448993.
We demonstrated a high output power distributed-Bragg-reflector (DBR) laser integrated with semiconductor optical amplifier (SOA) for the frequency-modulated continuous-wave (FMCW) light detection and ranging (LiDAR) system. In order to acquire higher output power, different from the conventional SG-DBR laser, the front mirror in this work is a section of uniform grating to get higher transmissivity. Therefore, the output power of the laser reaches 96 mW when the gain current and SOA current are 200 mA and 400 mA, respectively. Besides, we fabricated a spot size converter (SSC) at the laser output port to enhance the fiber coupling efficiency, which reached 64% coupled into the lensed fiber whose beam waist diameter is 2.5 μm. A tuning range of 2.8 nm with free spectral range (FSR) of 0.29 nm and narrow Lorentzian linewidth of 313 kHz is achieved. To realize distance and velocity measurement, we use the iterative learning pre-distortion method to linearize the frequency sweep, which is an important part of the FMCW LiDAR technology.
我们展示了一种集成半导体光放大器（SOA）的高输出功率分布布拉格反射器（DBR）激光器，用于调频连续波（FMCW）光探测和测距（LiDAR）系统。为了获得更高的输出功率，与传统的采样光栅DBR激光器不同，本工作中的前镜是一段均匀光栅，以获得更高的透射率。因此，当增益电流和SOA电流分别为200 mA和400 mA时，激光器的输出功率达到96 mW。此外，我们在激光器输出端口制作了一个光斑尺寸转换器（SSC），以提高光纤耦合效率，耦合到束腰直径为2.5μm的透镜光纤中的耦合效率达到了64%。实现了2.8 nm的调谐范围，自由光谱范围（FSR）为0.29 nm，洛伦兹线宽窄至313 kHz。为了实现距离和速度测量，我们使用迭代学习预失真方法对频率扫描进行线性化，这是FMCW LiDAR技术的一个重要部分。
