A rugged resonator for a laser includes a laser pump housing. An X-fold resonator assembly is configured to receive and hold the laser pump housing. The resonator includes at least four mirrors, a first, a second, a third, and a fourth mirror. The first mirror is configured to receive a first incident laser beam from the first end and to reflect a first reflected beam to reflect as a third reflected beam from the third mirror. The second mirror is configured to receive a second incident laser beam from the second end and reflecting a second reflected beam to intersect the first reflected beam and to reflect as a fourth reflected beam from the fourth mirror. An optical coupler is affixed to an optics plate and configured to receive the third reflected beam. A high reflector is affixed to the optics plate and configured to receive the fourth reflected beam.
In an optical amplifying device, an optical beam passes multiple times through a grazing-incidence bounce amplifier, accessing different parts (G1,G2) of the gain region on each transit. This provides improved characteristics in beam quality, with higher power scalability. The multipass configuration can operate as a high gain amplifier device and, with the addition of suitable feedback such as reflectors (M1-M4), as a laser oscillator to provide an optical source.