Abstract: The present invention provides a laser device wherein one diffraction grating and at least two reflectors are arranged such that two coupled resonators are formed for the light path. This laser device is an arrangement forming a first optical resonator comprising a first and a second reflector including in its light path the diffraction by the grating. The second reflector is arranged perpendicularly to an order of diffraction of the grating. Coupled with the first resonator (A), there is provided a second mirror-reflective resonator between a mirror-reflective surface of the grating and the second reflector. In the case of the grating having an even number of ports, the second resonator needs completion by a third reflector arranged to reflect light from specular reflection by the grating back to the grating. For gratings having an odd number of ports, the second reflector is arranged in parallel to the grating. The laser medium is preferably arranged between the first reflector and the grating.