Developmental Research of a Tunable Far Infrared Laser Using Germanium

项目已经开始，唯一可用的振荡是当锗样品本身作为光学谐振器时的波导模。在本项目中，总结了以下进展，为在振荡光谱范围内实现波长的机械调谐提供了良好的前景。1)在带外反射镜的半共焦谐振腔中实现了轴模的振荡。2)在谐振器中加入附加结构作为法布里-珀罗涉器进行波长选择，虽然在实验中证实了这一原理是可行的，但由于增益系数较小，这种选择在实际应用中并不完全令人满意。3)为了提高增益系数，对单轴应力下的振荡进行了研究，取得了显著的效果，为以后的工作提供了良好的前景。

Berofe the project had started, the only oscillation available was od waveguide modes wher Germanium specimens by themselves sereve as the optical resonator. In this project, the developments summarized below have been achieved leading to promissing prospects for mechanical tuning of wavelength over entie range of oscillation spectrum.1) Oscillation of axial modes was achieved in semiconfocal resonators with external mirrors. The directivity of the laser beam was thereby improved significantly, making possible detailed studies of the spectrum, the polarization and he gain-coefficient of oscillations.2) Wavelenght selection was attemped by incorporation an additinal structure into the resomator to work as a Fabri-Perot interfermeter.Although the principle was confirmed to work in the experiments, the selectivity was not completely satistactory in veiw of application vecause of relatively small gain-coefficients. It thus turned out the improving the gain-coefficients is necessary for the selection and the tuninf of wavalength.3) To improve gain-coefficients, studies of oscillation under uniaxial stress has been carried out, which proved to be strikingly effective thus providing promissing prospects for the future work.