Patent ID: 7826501

Claim:
A mode hop-free tunable laser comprising: a gain medium, a control device, a microfabricated blazed grating, defining an external cavity of a given length, said blazed grating lying in a general plane and comprising: a plurality of elongate beams carrying mutually parallel respective reflection surfaces spaced apart from one another with a predefined pitch, each of said reflection surfaces having a normal direction inclined at an angle α to the normal direction of said general plane, said beams defining an assembly the position of which defines said cavity length; said reflection surfaces being substantially normal to the incident light beam provided by the gain medium; and actuating elements designed so as to apply, with possibly asymmetrical forces to the grating extremities, a stretching and a displacement of said assembly within a plane substantially parallel to said grating general plane, said actuating elements being a first and a second pairs of comb electrodes, one end of which being fastened to said assembly and the other end being fastened to said grating support said control device being designed to possibly act on said actuating elements, so as to enable: a uniform modification of said pitch in order to adjust the wavelength of a light beam diffracted by said grating; and a control of said cavity length so as to allow the phase of the light beam diffracted by said grating to be adjusted independently of said adjustment of its wavelength leading to a mode hop-free tuning of the tunable laser.