新型高功率小孔耦合内腔光泵THz激光技术研究

The project is a new designed intra-cavity optically pumped THz laser to improve the laser power and pump efficiency, which is based on the current research situation of the optically pumped THz laser and our previous work. The project overcomes the limitation of the THz band material and lens coating technology for intra-cavity optically pumped THz laser. The pump laser intensity in the cavity is larger than extra-cavity under the same condition, so the THz laser with high efficiency and high output power is easily obtained, and the pumped efficiency can be improved about 10 times in this project. The pulsed THz laser with high pulse repetition rate can be obtained by high speed rotating chop plate in the cavity. This project theoretically calculate and simulate the optical field distribution in the cavity and dynamic equation of intra-cavity THz laser, while design the new resonator with round hole and make analysis for the W-level THz laser output would be obtained in the experiment. The outbreak of this project will lay important foundation for practical application of THz-band in the fields of high speed THz imaging, THz laser radar and THz laser non-damage detection.

本项目针对目前光泵THz激光效率较低的研究现状，在我们前期研究高重频光泵THz激光器的基础上，提出了一种新型小孔耦合内腔光泵THz激光谐振腔，克服了目前内腔光泵THz激光谐振腔所需的THz波段的镜片材料及镀膜技术的限制。由于在相同条件下泵浦激光在腔内光强远强于腔外，因此内腔光泵结构的THz激光器泵浦总效率可以提高到10倍以上，可以获得高功率THz激光输出。另外通过腔内高速斩波可实现高重复频率高功率脉冲THz激光输出。本项目重点是对谐振腔内光场建立数学模型进行模拟仿真，对激光动力学过程进行理论分析与计算，合理设计新型小孔输出稳定谐振腔参数，通过实验研究获得平均功率达到瓦量级的THz激光输出。此项研究的进展，将为光泵THz激光技术的发展带来较大的突破，可应用于高速THz成像、THz激光雷达、THz激光无损探测等领域，为THz激光在实际中更广泛的应用奠定基础。

本项目针对目前光泵THz激光效率较低的研究现状，研究高重频光泵THz激光器的基础上，研制了一种新型小孔耦合光泵THz激光谐振腔可以获得高功率THz激光输出。本项目通过直流放电激励CO2激光管作为泵浦激光器，采用一级反射率大于95%，光栅常数为150lines/mm的闪耀光栅选支，泵浦CH2F2和CH3OH等气体，通过调整泵浦谱线获得多条THz激光输出，泵浦激光最高40W，最高输出功率为150mW，具有较高的稳定性。并且提出采用旋转F-P硅片的方法测量THz激光的波长，该激光器具有造价低，结构简单的优点，可应用于高速THz成像、THz激光雷达、THz激光无损探测等领域，为THz激光在实际中更广泛的应用奠定基础。