Laser Physics

, 18:939

Quasi-common-path microchip laser feedback interferometry with a high stability and accuracy

Solid State and Liquid Lasers


We report on an improved scheme of quasi-common-path microchip laser feedback interferometry, which demonstrates a high stability and accuracy. An additional beam splitter is used to divide the external cavity into a measuring feedback cavity and a reference feedback cavity. With this scheme, the optical path lengths of the measuring and reference feedback light can be made nearly the same, thus greatly reducing the long-period phase fluctuation caused by the laser frequency drift. The final system performances are evaluated as followed: the short-term displacement resolution is better than 2 nm, the output fluctuation is less than 10 nm within a 40-min-long stability test, and the maximum error within the 100-μm range is 25 nm when calibrated with the Agilent 5529A dual-frequency laser interferometer.

PACS numbers

42.62.Eh 07.60.Ly 42.25.Hz 42.55.Xi 

Copyright information

© Pleiades Publishing, Ltd. 2008

Authors and Affiliations

  1. 1.State Key Laboratory of Precision Measurements, Department of Precision InstrumentsTsinghua UniversityBeijingChina

Personalised recommendations