Evaluation of quantum-cascade lasers as local oscillators for infrared heterodyne spectroscopy.
Evaluation of quantum-cascade lasers as local oscillators for infrared heterodyne spectroscopy.
复制标题
量子级联激光器作为红外外差光谱本地振荡器的评估。
DOI：
10.1364/ao.44.007170
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发表时间：
2005
期刊：
影响因子：
1.9
通讯作者：
R. Schieder
中科院分区：
文献类型：
--
作者：
G. Sonnabend;D. Wirtz;R. Schieder
我们报告的实验评估的可行性，量子级联激光器（QCL）在中红外波长作为本机振荡器（LO）的外差接收机。连续波（cw）激光器约9.6和9.2微米的性能测试进行了调查光输出功率，激光线宽，和可调谐性。并与CO_2气体激光器本振进行了直接比较。在外差光谱仪中实现的系统灵敏度仅为量子极限以上的2倍，并且测得的线宽小于1.5 MHz，这表明QCL是适合外差光谱的激光源，具有足够的输出功率，即使在高灵敏度天文外差接收器中也可以取代气体激光器作为LO。此外，我们的实验表明，激光器的可调谐性可以大大提高通过使用外腔。
We report experiments evaluating the feasibility of quantum-cascade lasers (QCLs) at mid-infrared wavelengths for use as local oscillators (LOs) in a heterodyne receiver. Performance tests with continuous-wave (cw) lasers around 9.6 and 9.2 microm were carried out investigating optical output power, laser linewidth, and tunability. A direct comparison with a CO2 gas laser LO is presented as well. The achieved system sensitivity in a heterodyne spectrometer of only a factor of 2 above the quantum limit together with the measured linewidth of less than 1.5 MHz shows that QCLs are suitable laser sources for heterodyne spectroscopy with sufficient output power to replace gas lasers as LOs even in high-sensitivity astronomical heterodyne receivers. In addition, our experiments show that the tunability of the lasers can be greatly enhanced by use of an external cavity.