论文部分内容阅读
一般的干涉现象为“反射镜每移动半个波长,出现一个干涉条纹”。介绍了利用激光回馈获得纳米级宽度干涉条纹的方法。系统构成:He-Ne激光器,使用近于全反射的球面介质镜作激光器的回馈镜,且该回馈镜法线和激光束夹分量级的小角度。回馈镜沿激光束位移移动时,激光器的功率发生周期类正旋波动,即产生回馈干涉条纹。回馈镜离激光器越近,条纹越窄,以至于半波长位移中出现40个条纹。对波长为632.8 nm的He-Ne激光器而言,每个条纹宽度为7.91 nm。同时,当回馈镜的运动方向发生变化时,激光的偏振态将在两个正交的方向之间发生跳变。利用此效应,可以实现纳米分辨位移测量和回馈镜运动方向的识别。
The general phenomenon of interference is “an interference fringe occurs every half wavelength of the mirror.” The method of obtaining nanometer width interference fringes by using laser feedback is introduced. System composition: He-Ne laser, the use of near-total reflection of the spherical dielectric mirror as the laser feedback mirror, and the feedback mirror and the laser beam sandwiching the order of small-angle. When the feedback mirror moves along the laser beam displacement, the positive periodic fluctuation of the power generation period of the laser generates feedback interference fringes. The closer the feedback mirror is to the laser, the narrower the stripe so that 40 stripes appear in the half-wavelength shift. For a He-Ne laser with a wavelength of 632.8 nm, the width of each stripe is 7.91 nm. At the same time, when the direction of motion of the feedback mirror changes, the polarization state of the laser will jump between two orthogonal directions. Using this effect, it is possible to realize the nano-resolution displacement measurement and the recognition of the movement direction of the feedback mirror.