Weidmann D, Joly L, Parpillon V, Courtois D, Bonetti Y, Aellen T, Beck M, Faist J, Hofstetter D
Groupe de Spectroscopie Moléculaire et Atmosphérique, Faculté des Sciences, Université de Reims Champagne-Ardenne, BP 1039, 521687 Reims Cedex 2, France.
Opt Lett. 2003 May 1;28(9):704-6. doi: 10.1364/ol.28.000704.
We report spectral linewidth measurements of a 9.1-microm distributed-feedback quantum cascade laser (QCL). The free-running QCL beam was mixed with a waveguide isotopic C18O2 laser onto a high-speed HgCdTe photomixer, and beat notes were recorded from a radio-frequency spectral analyzer. Beating was performed at two operating conditions, first near the QCL laser threshold (beating with the C18O2 R10 line) and then at a high injection current (beating with the C18O2 R8 line). Overall, beat note widths of 1.3-6.5 MHz were observed, which proves that a free-running QCL can have a short-term spectral width near 1 MHz.
我们报告了对一台9.1微米分布反馈量子级联激光器（QCL）的谱线宽度测量结果。将自由运转的QCL光束与一台波导同位素C18O2激光器混合到一个高速HgCdTe光混频器上，并从射频频谱分析仪记录拍频信号。在两种工作条件下进行拍频，首先是在QCL激光阈值附近（与C18O2的R10线拍频），然后是在高注入电流下（与C18O2的R8线拍频）。总体而言，观察到拍频信号宽度为1.3 - 6.5兆赫，这证明自由运转的QCL可以具有接近1兆赫的短期谱宽。
