量子级联激光器是一种新型的红外相干光源。 利用量子理论与带隙工程, 量子级联激光器可实现3 μm到100 μm波长范围内的任意输出波长。 由于大多数气体分子的特征光谱都集中在中红外波段, 而中红外量子级联激光器具有功率高、 线宽窄、 扫描速度快等独特的优点, 因此, 基于量子级联激光器的红外光谱技术已成为气体检测技术的研究热点。 尤其是, 近年来室温激光器性能得到不断的完善, 输出功率和电光转换效率得到了极大的提高, 这在很大程度上推动了红外激光光谱技术的迅速发展。 本文根据工作原理, 分别介绍了基于直接吸收谱检测、 相位调制光谱检测、 光声调制光谱检测和法拉第旋光效应光谱检测的量子级联激光器红外光谱检测技术, 并对其实现方法和应用情况进行了介绍。

Quantum cascade lasers (QCLs) are promising infrared coherent sources. Thanks to the quantum theory and band-gap engineering, QCL can access the wavelength in the range from 3 to 100 μm. Since the fingerprint spectrum of most gases are located in the mid-infrared range, mid-infrared quantum cascade laser based gas sensing technique has become the research focus world wide because of its high power, narrow linewidth and fast scanning. Recent progress in the QCL technology leads to a great improvement in laser output power and efficiency, which stimulates a fast development in the infrared laser spectroscopy. The present paper gives a broad review on the QCL based spectroscopy techniques according to their working principles. A discussion on their applications in gas sensing and explosive detecting is also given at the end of the paper.