Patent ID: 7873081

Claim:
A wavelength tunable laser comprising: (a) an output mirror and an end mirror each having prescribed reflectivity to form a laser cavity; (b) a wavelength tunable laser medium disposed in said laser cavity and capable of laser oscillation in a wavelength spectrum of a prescribed range; (c) an acousto-optical filter disposed in the said laser cavity and to which is inputted the outgoing light from said wavelength tunable laser medium by a collimating lens; said filter comprising an acoustically anisotropic and optically birefringent crystal; means for exciting an acoustic wave in said crystal comprising a first acoustical transducer and second acoustical transducer bonded opposite to each other to selected surfaces of said crystal, a first and second acousto-optical diffraction means are formed as a first acoustic field and second acoustic field counter propagating in a single acousto-optical crystal for optical dispersion compensation and wavelength shift compensation; (d) said acousto-optical filter, said output mirror and said end mirror of said laser cavity being arranged so as to reflect only a light component which is diffracted by said acousto-optical filter; (e) a source of radio frequency electrical power for providing radio frequency energy to said transducers for tuning the cavity oscillation wavelength by changing the radio frequency; (f) a radio frequency signal phase delay line capable of adjusting the two radio frequency signal phases by 0 to 180 degrees; (g) means for exciting said laser gain medium; (h) a base for the said cavity end mirror attached to a PZT element; (i) a PZT driver to activate said PZT element; and (j) an intracavity collimating lens for collimating laser beam inputting to said filter.