类比式相位差低同调光学反射技术的研究

Study on analogical differential-phase low homological optical reflecting technique

为了获得更高的测量解析度,采用低同调光源和迈克尔逊干涉仪为主要结构,结合差动放大器与高倍显微物镜测量发展了一套类比式相位差低同调光学反射系统。该系统其利用类似平衡检测的结构可获得高信噪比和高灵敏度的测量能力;使用频宽为100MHz的差动放大器,可得到高时间-频宽乘积的测量,能在表面形貌和移动速率测量上达到更高的灵敏度。结果表明,该系统使用了频宽较窄的超发光二极管与高数值孔径的显微物镜进行局域测量,使其具有相同的局域定位效果。

In order to obtain higher measurement resolution, an analogical differential-phase low homologieal optical reflecting system was developed with a differential amplifier combined with a high magnification microscope objective lens based on a low homological light source and a Michelson interferometer. High signal-to-noise ratio and high sensitivity can be obtained by means of the balanced detecting structure. The high time-frequency width product can be acquired by using the differential amplifier with frequency width of 100MHz. Thus a higher sensitivity can be achieved for measuring the surface morphology and moving rate. The result indicates that the local measurement by use of a super luminiferous diode （SLD） with narrow frequency width and a microscope objective with large number aperture has the same effect on local location.