A simple and compact laser resonator is proposed which makes it possible
to symmetrically operate a gain medium, preferably a semiconductor, which
possesses more than one channel of emission. As a result higher output
powers and/or better beam qualities and/or better spectral
characteristics can be achieved. The resonator is very compact and
ideally comprises only three optical elements: a laseractive gain medium
(1), a cylindrical collimation lens (5), and a prism (6) which is adapted
to the angle between the two emissions (4) and which carries a beam
splitter (7) and a feedback mirror (9) on its faces. Preferably the gain
medium (1) possesses a feedback element (2) and an antireflective coating
(3) on its faces. If no antireflective coating (11) is desired the same
effect can be achieved by arranging the angle of incidence to fulfill the
Brewster-condition. In a preferred embodiment the gain medium (1) is a
high-power diode laser chip with an internal stripe-array and/or the
laser resonator is unstable along the direction parallel to the epitaxial
layers. In alternative embodiments the feedback element (9) is wavelength
selective like a grating, a dielectric filter, a holographic element or a
volume Bragg grating.