We have developed a system to measure absolute distance. By stabilizing the output direction of dye laser, improving the accuracy of the wavelength and reducing the non-linear errors caused by stray beams, an accuracy of +or-1.3 nm and a resolution of 0.2 nm were obtained for a range of 100 mm. In our system, as wavelengths could be set free, a systematic procedure, i.e., setting synthetic wavelengths in a geometric ratio to minimize the number of output wavelengths within a range to be measured, became possible and greatly extended the range. Our proposal seems to be an original one.
展开▼
