Serrodyne optical frequency shifting for heterodyne self-mixing in a distributed-feedback fiber laser

摘要

We describe an all-fiberized coherent detection system at 1.55 u0001m using heterodyne self-mixing modulationnin a distributed-feedback fiber laser. Frequency shifting of the optical feedback is based on serrodyne phasenmodulation with an integrated electro-optic modulator, which is a significant advance in the simplification ofnthe self-mixing detection scheme for class B lasers. Accurate measurement of the optical phase differencenbetween the laser electric field and the backscattered electric field demonstrates nanometric displacementndetection on noncooperative targets. © 2008 Optical Society of America