- An absolute distance heterodyne interferometer using a dual longitudinal mode He Ne laser is proposed.
- An optic interferometer system based on optical multiplication for measuring absolute distance was presented.
- Output power equalization of laser dual spectrum lines is a special requirement which is put on its laser source by two wavelength beat-wave absolute distance interferometry.
- Thirdly, different judging criteria, including absolute distance, Euclidian distance and similarity matching, are adopted to match different requirements on recognition speed or accuracy.
- The phase errors, resulting from the multi beam interference in the Fabry Perot cavities of the wavelength scanning fiber optic interferometer for absolute distance measurement, are analyzed.
- The technology of non-contact, large-range and high-accuracy absolute distance measurement plays an important role in nowaday measument technology with a bright future in application.