New optic fiber interferometer system for absolute distance measurement

An absolute distance measurement system which fulfill, the requirements for absolute measurement of long distance (over 1 meter) only using short scanning guide rail (about 200 millimeter), and consists of the locating interferometer and the scanning interferometer is presented the locating measuring processes of the object are divided to achieve absolute measurement. The optical fiber interferometer is adopted to improve the flexibility and the anti jamming capability of the measuring system. Furthermore, several optical fiber groups that have different original optical retardation are used in the locating interferometer to fulfill the multiplication of the measuring range. The system can be used to calibrate the original optical retardation of the optical fiber groups by itself. The experiments illustrate that the relative measuring accuracy can reach 10(-5).