Patent ID: 7564880

Claim:
A wavelength-adjustable laser, comprising: a. a gain medium for amplifying a laser beam in a wavelength range; b. a first optical reflector; c. an acousto-optical modulator located between the gain medium and the first optical reflector such that the acousto-optical modulator diffracts a portion of the laser beam into a plurality of diffracted laser beams wherein each diffracted laser beam diffracts at a different angle from an optical axis formed by the laser beam based on the wavelength of the diffracted laser beam and a radio frequency signal used to drive the acousto-optical modulator; d. a second optical reflector and a third optical reflector positioned about the optical axis such that only a selected diffracted laser beam from the plurality of diffracted laser beams is reflected off both the second optical reflector and the third optical reflector into the acousto-optical modulator; e. an adjustable radio-frequency source coupled to the acousto-optical modulator wherein the wavelength of the selected diffracted laser beam is changed by adjusting the frequency of a radio signal emitted from the adjustable radio-frequency source; f. an amplitude of the adjustable radio frequency source having been selected to increase a loss in a zero order diffracted beam from the acousto-optical modulator for all wavelengths lying within a gain curve thereby having forced beam amplitude at these wavelengths below a laser threshold; g. an alignment of the acousto-optical modulator having been adjusted to equalize diffraction efficiencies of plus and minus first orders; h. an alignment of the second and third optical reflectors having been adjusted to return only first diffracted orders for the selected radio frequency drive frequencies, back into the acousto-optical modulator and through the gain medium, thereby having elevated the amplitude above the laser threshold and having allowed the selected optical frequencies to lase; and i. an alignment of the first optical reflector having been adjusted to return the zero order diffracted beam emerging from the acousto-optical modulator back along a same path.