Frequency Stabilization of Semiconductor Laser for Optical Metrology

光学计量用半导体激光器的稳频

• 批准号: 02650189
• 负责人: TANAKA Keiichi
• 金额: $ 0.13万
• 依托单位: Tokyo Denki University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1990
• 资助国家: 日本
• 起止时间: 1990 至 1991
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-02650189/
• 关键词: semiconductor laser; spectral width; optical feedback; interference spectrometry; visibility of interference fringe; optical phase modulation; フ-リエ分光法

Experimental research for measuring spectral width of visible semiconductor lasers has been done, aiming to stabilize frequency of semiconductor laser at an absorption line of a molecule.1. Behavior of oscillation mode of 670nm semiconductor laser, which depends on optical feed back, was investigated. A Frabry-Perot etalon with a simple structure was made for filtering single frequency peak of multimode output of the laser. It shows good attenuation of side lobes.2. A scanning Michelson interferometer was made to measure visibility active as a function of optical path difference. The obtained curve makes possible to calculate optical patil length of the semiconductor laser and also oscillation mode can be analyzed.3. Optical phase modulation of 633nm beam of a He-Ne laser at modulation frequency of 50 and 100MHz was examined and a clear peak of sideband was observed by optical beat detection. The results shows that the sideband will be useful for detecting molecular absorption lines since its central frequency can be swept by changing modulation frequency. This system can be used for the semiconductor laser.4. Detection of optical beat note, which should be generated by mixing 670nm beams of two semiconductor lasers, was done intending to measure the spectral width. In spite of precise alignment of optical axises and wave surface of both beams and fine tuning of the oscillation frequency of the lasers, the beat has not detected. This is the most important and necessary measurement for stabilizing the laser at a narrow molecular absorption line. We will continue this experimental research improving our measuring system and blushing tip our experimental technique.

为了使半导体激光器的频率稳定在某一分子的吸收线上，进行了测量可见半导体激光器光谱宽度的实验研究。研究了依赖光反馈的670nm半导体激光器振荡模式的特性。制作了一个结构简单的frabrry - perot标准子，用于滤波多模输出的单频峰。它显示了良好的侧瓣衰减。利用扫描式迈克尔逊干涉仪测量可见光随光程差的变化。得到的曲线可以计算半导体激光器的光粒子长度，也可以分析振荡模式。研究了调制频率为50和100MHz的氦氖激光器633nm光束的光学相位调制，通过光学拍频检测观察到一个清晰的边带峰。结果表明，改变调制频率可以扫过边带的中心频率，因此边带可以用于检测分子吸收线。该系统可用于半导体激光器。对两束半导体激光器670nm光束混合产生的光拍音进行了检测，目的是测量光谱宽度。尽管对两束光束的光轴和波面进行了精确的对准，并对激光器的振荡频率进行了微调，但仍未检测到这种跳动。这是在窄分子吸收线上稳定激光的最重要和必要的测量。我们将继续这项实验研究，改进我们的测量系统，改进我们的实验技术。