F-P标准具特性研究及高准确度波长测定仪的研制

Resarch and development of a F-P etalon characteristics investigating and high-accuracy wavelength measuring instrument

漫射单色光经F-P标准具产生一组干涉圆环,利用小数重合法来求解圆环中心干涉级次的小数部分.实验采用一条氦线、一条氖线和几条波长相近的汞线作光源,同时获得经F-P标准具的多波长干涉圆环.对圆环的点位坐标数据作圆回归求直径值及其标准差,进而用新的准直线模型作加权回归求得各波长的小数干涉级次,评定其扩展不确定度.由三个波长的测量结果用小数重合法计算,求得间隔d±Δd=(3 096 977.97±1.76)nm.

A set of concentric interference circles is formed for diffused monochromatic light illuminated a F-P etalon. Fractional orders at the centre of the interference fringes are determined by excess fraction method. The spec- trum of the light source consists of certain adjacent wavelengths,including one He line,one Ne line, and a few Hglines. Thus images of the resulting sets of interierence circles are obtained simultaneously by a digital camera at the focal plane of the imaging lens. The diameters and standard deviations are computed by the circular regression of coordinate data. The fractional orders are calculated by weighted regressions in a new quasi-linear model, and the expanded uncertainties are assessed corresponding to different wavelengths. Inducing three of the wavelengths to the process to solve the fraction orders by excess fraction method,the spacer d of the F-P etalon is calculated to be d± Ad=（3 096 977.97±1.76）nm.