基于猫眼腔镜损耗调节的激光横模演示系统

提出一种基于猫眼腔镜损耗调节的新型激光横模演示系统。采用半外腔He-Ne激光器,利用由分立的可进行五维微调的凸透镜和凹面镜组成的猫眼逆向器构成损耗可调激光谐振腔,通过调节猫眼逆向器改变激光谐振腔的损耗比，实现改变激光横模状态的作用。利用CCD进行图像采集，计算机实现图像存储，从而得到20多种结构清晰的高阶横模花样图片。     

Influence of Feedback Levels on Polarized Optical Feedback Characteristics in Zeeman-Birefringence Dual Frequency Lasers

The influence of feedback levels on the intensity and polarization properties of polarized optical feedback in a Zeeman-birefringence dual frequency laser is systematically investigated. By changing the feedback power ratio, different feedback levels are obtained. Three distinct regimes of polarized optical feedback effects are found and defined as regimes Ⅰ, Ⅱ and Ⅲ The feedback level boundaries among the regimes are acquired experimentally. The theoretical analysis is presented to be in good agreement with the experimental results.     

Anisotropic optical feedback of single frequency intra-cavity He--Ne laser

This paper presents the anisotropic optical feedback of a single frequency intra-cavity He--Ne laser. A novel phenomenon was discovered that the laser output an elliptical polarized frequency instead of the initial linear polarized one. Two intensities with a phase difference were detected, both of which were modulated in the form of cosine wave and a fringe shift corresponds to a λ/2 movement of the feedback mirror. The phase difference can be continuously modulated by the wave plate in the external cavity. Frequency stabilization was used to stabilize the laser frequency so as to enlarge the measuring range and improve the measurement precision. This anisotropic optical feedback system offers a potential displacement measurement technology with the function of subdivision of λ/2 and in-time direction judgment. The three-mirror Fabry--Perot cavity model is used to present the experimental results. Given the lack of need of lasing adjustment, this full intra-cavity laser can significantly improve the simplicity and stability of the optical feedback system.