Sharpe S W, Kelly J F, Hartman J S, Gmachl C, Capasso F, Sivco D L, Baillargeon J N, Cho A Y
Opt Lett. 1998 Sep 1;23(17):1396-8. doi: 10.1364/ol.23.001396.
Lasing characteristics were evaluated for distributed-feedback quantum-cascade (QC) lasers operating in a continuous mode at cryogenic temperatures. These tests were performed to determine the QC lasers' suitability for use in high-resolution spectroscopic applications, including Doppler-limited molecular absorption and pressure-limited lidar applications. By use of a rapid-scan technique, direct absorbance measurements of nitric oxide (NO) and ammonia (NH>(3)) were performed with several QC lasers, operating at either 5.2 or 8.5 microm. Results include time-averaged linewidths of better than 40 MHz and long-term laser frequency reproducibility, even after numerous temperature cycles, of 80 MHz or better. Tuning rates of 2.5 cm(-1) in 0.6 ms can be easily achieved. Noise-equivalent absorbance of 3 x 10(-6) was also obtained without optimizing the optical arrangement.
对在低温下连续工作的分布反馈量子级联（QC）激光器的激射特性进行了评估。进行这些测试是为了确定QC激光器是否适用于高分辨率光谱应用，包括多普勒极限分子吸收和压力极限激光雷达应用。通过使用快速扫描技术，使用几个工作在5.2或8.5微米波长的QC激光器对一氧化氮（NO）和氨（NH₃）进行了直接吸光度测量。结果包括时间平均线宽优于40 MHz，以及即使经过多次温度循环后仍具有80 MHz或更好的长期激光频率再现性。在0.6毫秒内轻松实现2.5 cm⁻¹的调谐速率。在未优化光学装置的情况下，也获得了3×10⁻⁶的噪声等效吸光度。
