Real-time drift error compensation in a self-reference frequency-scanning fiber interferometer

In order to eliminate the fiber drift errors in a frequency-scanning fiber interferometer, we propose a self-reference frequency-scanning fiber interferometer composed of two fiber Michelson interferometers sharing common optical paths of fibers. One interferometer defined as reference interferometer is used to monitor the optical path length drift in real time and establish a measurement fixed origin. The other is used as a measurement interferometer to acquire the information from the target. Because the measured optical path differences of the reference and measurement interferometers by frequency-scanning interferometry include the same fiber drift errors, the errors can be eliminated by subtraction of the former optical path difference from the latter optical path difference. A prototype interferometer was developed in our research, and experimental results demonstrate its robustness and stability.