Abstract: A monolithic self-Q-switched laser generates laser pulses with short duration, high peak power, a single longitudinal mode, and extremely small pulse-to-pulse intensity fluctuations. The laser comprises of a length of solid-state laser material with a plurality of dopants, so that the material can generate coherent radiation for laser action and, in the same material, provide saturable absorption at the wavelength of the laser emission necessary for Q-switching. The distributed saturable absorber in the material provides a spectral stabilization mechanism that ensures single longitudinal-mode operation. The laser cavity is formed by the two end surfaces of the solid-state laser material with appropriate reflectivity coatings. When the laser material is pumped above the threshold condition, the laser device produces short pulses having high peak power in a single longitudinal mode and single transverse mode.

Abstract: A phase conjugation mirror (20) for use in a phase conjugation resonator (1). The phase conjugation mirror provides a nonlinear resonance enhancement for a coherent optical signal incident thereon. The phase conjugation mirror is comprised of a semiconductor material having a characteristic bandgap energy selected to be at an absorption bandgap edge, or slightly greater than the absorption bandgap edge, for the coherent optical signal.