Razeghi M, Lu Q Y, Bandyopadhyay N, Zhou W, Heydari D, Bai Y, Slivken S
Opt Express. 2015 Apr 6;23(7):8462-75. doi: 10.1364/OE.23.008462.
The quantum cascade laser (QCL) is an important laser source in the mid-infrared and terahertz frequency range. The past twenty years have witnessed its tremendous development in power, wall plug efficiency, frequency coverage and tunability, beam quality, as well as various applications based on QCL technology. Nowadays, QCLs can deliver high continuous wave power output up to 5.1 W at room temperature, and cover a wide frequency range from 3 to 300 μm by simply varying the material components. Broadband heterogeneous QCLs with a broad spectral range from 3 to 12 μm, wavelength agile QCLs based on monolithic sampled grating design, and on-chip beam QCL combiner are being developed for the next generation tunable mid-infrared source for spectroscopy and sensing. Terahertz sources based on nonlinear generation in QCLs further extend the accessible wavelength into the terahertz range. Room temperature continuous wave operation, high terahertz power up to 1.9 mW, and wide frequency tunability form 1 to 5 THz makes this type of device suitable for many applications in terahertz spectroscopy, imaging, and communication.
量子级联激光器（QCL）是中红外和太赫兹频率范围内的一种重要激光源。在过去的二十年里，它在功率、壁插效率、频率覆盖范围和可调谐性、光束质量以及基于QCL技术的各种应用方面都取得了巨大的发展。如今，QCL在室温下能够输出高达5.1 W的高连续波功率，并且通过简单改变材料成分就能覆盖从3到300μm的宽频率范围。具有3至12μm宽光谱范围的宽带异质QCL、基于单片采样光栅设计的波长捷变QCL以及片上光束QCL合束器正在被开发，用于下一代用于光谱学和传感的可调谐中红外光源。基于QCL中的非线性产生的太赫兹源进一步将可及波长扩展到太赫兹范围。室温连续波运行、高达1.9 mW的高太赫兹功率以及1至5 THz的宽频率可调谐性使得这类器件适用于太赫兹光谱学、成像和通信中的许多应用。
