Development of optical feedback technology of LD pumped microchip lasers

The development of optical feedback technology of LD pumped microchip Nd:YAG lasers is reviewed.At first its research background and basic theoretical model are introduced.Then its applications such as ultrahigh sensitivity self-mixing laser Doppler velocimeters,nanometer vibrometers and laser optical feedback tomography are described in detail.Finally some predictions of its future development are also presented.