为了获得窄线宽太赫兹光源，制作了基于表面金属光栅的单模太赫兹量子级联激光器。通过优化光栅结构，获得了具有较强耦合效率和较低损耗的光栅结构参数。波导结构采用半绝缘表面等离子体波导以便能获得较高的光输出功率。激光器单模激射波长为 95 μm。10 K时，器件最高单模输出功率达到了 43 mW，单模抑制比为 18 dB。单模器件工作温度超过 70 K，在 70 K时，仍然有 5 mW的单模输出功率。这种输出性能良好的激光器有望作为太赫兹接收机的本振源。

A single-mode terahertz quantum cascade laser with metallic surface gratings is fabricated in order to obtain a terahertz source with narrow line width. Strong coupling efficiency and low waveguide loss are realized. A semi-insulating surface-plasmon waveguide is used to present a high output power. The lasing wavelength of this laser is 95 μm. The highest optical power of 43 mW and Side-Mode Suppression Ratio(SMSR) of 18 dB can be obtained under 10 K. Under the highest operation temperature of 70 K, an output power of 5 mW is still achieved. This kind of laser is the most promising solid-state source as the Local Oscillator(LO) for a high resolution terahertz heterodyne receiver.