Patent ID: 7720117

Claim:
A laser device, comprising: a laser gain medium configured to produce a first laser beam; a mode-selection filter configured to receive the first laser beam and to produce a second laser beam that comprises a plurality of spectral peaks having first line widths, wherein two of the plurality of spectral peaks are separated by a frequency difference, wherein the mode-selection filter comprises: a first reflective plate configured to receive the first laser beam orthogonal to the first reflective plate; a second reflective plate parallel to the first reflective plate; and an optical material disposed between the first parallel reflective plate and the second reflective plate wherein the optical material is an electro-optical material selected from a group consisting of LiNbO 3 , a semiconductor material, a PLZT, KTN (KTaNbO 3 ) and an electro-optical polymer, and configured to shift frequencies of the plurality of spectral peaks in response to an electric field; and wherein the first reflective plate, the optical material, and the second reflective plate are configured to filter the first laser beam to produce the second laser beam exiting the second reflection plate; a band-pass filter configured to filter the second laser beam and to produce a third laser beam having one of the plurality of spectral peaks; an optical sensor configured to output an output sensing signal in response to the third laser beam; and a controller configured to control the mode-selection filter in response to the output sensing signal to reduce fluctuations in power, frequency, or a combination thereof in the third laser beam.