摘要
外腔半导体激光的线宽小于100kHz,干涉相干距约为1000m,波长可调节范围超过100nm(1495—1645nm),应用上述二项特性,通过改变波长(频率)测得任意点到仪器的距离(不需要在测量计数时移动反光镜)。其测量距离大于100m,分辨率可以优于3nm,不确定度可以达到2.5×10^-6L,达到工程测量对测长仪器的要求。为提高测量不确定度,还可以使用2个或2个以上特定波长,通过小数重合法,更精确测得与被测点的距离,不确定度可以达到5×10^-7L。其优点是:测量时无需导轨移动测量镜(对比双频激光干涉仪)、可以挡光进行间断测量(对比激光跟踪仪)、测量不确定度和分辨率精度指标高(对比激光测距仪)。可以为尺寸大、形状复杂的几何物件和大型建筑物、基线场等精密测量提供十分有效的方法和工具。
A novel non-guideway laser interferometer for absolute long distance measurement is presented . An external cavity diode laser (ECDL) shows great selectivity to its wavelength, with a bandwidth less than 100 kHz and a coherent distance of about 1000 m. The wavelength can be continuously tuned from 1495 nm to 1645 nm. These two characteristics enable a wavelength-tun- ing interferometry for absolute long distance measurement. In the iuterferometry for measuring the distance of L, the resolution and uncertainty could be 3 nm and 2.5 × 10^-6L respectively, when the measuring range is about 100 m. In order to improve accura- cy, exact fraction method can be applied employing several specific wavelengths. By this means, the uncertainty could be up to 5 × 10^-7L.
出处
《计量学报》
CSCD
北大核心
2007年第2期110-113,共4页
Acta Metrologica Sinica
关键词
计量学
无导轨激光干涉仪
外腔半导体激光
不确定度
小数重合法
Metrology
Non-guideway laser interferometer
External cavity diode laser (ECDL)
Uncertainty
Exact fraction method