Quasi-white Light Optical Fiber Interferometer for Large Range Absolute Distance Measurement

A novel quasi-white light optical fiber interferometer for absolute distance measurement is puts forward. The system consists of locating interferometer and scanning interferometer, therefore, the location of objects and the measurement process are divided and absolute measurement can be achieved. Moreever, the locating interferometer adopts light switch and several accurately calibrated fiber groups of different optical retardation to realize the two-level multiplication of measurement range. Experiments have shown that the system can fulfill large range absolute measurement of more than 10 m only using short scanning guide of 200 mm with a high relative accuracy of 10~(-5).