Abstract: A solid-state laser having a rod of active material optically pumped along the side of the rod by an array of diode lasers. Beam shaping elements, such as Brewster angle facets on the end of the laser rod, cause the laser beam to assume a generally elliptical shape within the rod with the long axis of the ellipse aligned with the irradiation angle of the diode lasers. However, the beam is circularly shaped outside the rod. Preferably, the laser rod is held within an optical cavity formed within a cooling block which both cools the rod and reflects pump light back into the rod. The diode lasers irradiate the rod through a linear slit in the cooling block. Also, preferably, a slab-shaped optical waveguide is placed within the slit to guide the light from the diode lasers to the side of the laser rod.

Abstract: A stabilized solid-state laser in a thermal imaging system in which a laser diode pumps the solid-state laser and a modulator modulates the laser beam according to graphical data to be recorded in a thermally sensitive medium, as is used in the graphics industry. The solid-state laser is stabilized against relaxation oscillations induced in the laser by modulated light reflected back from the thermally sensitive medium. The light reflected from the medium is allowed to reenter the solid-state laser, but the optical output of the solid-state laser is sampled in the frequency band in which relaxation oscillations occur. The detected intensity is then used in a feedback circuit to control the intensity of the diode laser that is optically pumping the solid-state laser. Thereby, the data modulation does not cause the solid-state laser to oscillate, and neither a Faraday rotator nor use of a diffracted beam is required.

Abstract: A miniature laser cavity in which a solid-state lasing gain element and a Q-switch have respective end surfaces at substantially the Brewster angle, parallel to and facing each other, and separated by a narrow gap occupied by a transparent low-index-of-refraction material.

Abstract: A diode pumped Nd:YAG laser is disclosed wherein the YAG laser rod is supported from the envelope of the pumping diode by means of telescoping glass tubes bonded together by means of u.v. curing adhesive. The diode pumped laser is supported from a heat sink via the intermediary of a pair of rotatable wedges for adjusting the tilt of the optical axis of the laser. A gradient refractive index lens focuses the pump radiation into the laser rod. The lens is adhered directly to the output window of the pump diode by means of refractive index matching adhesive.

Abstract: A diode pumped Nd:YAG laser is disclosed. The YAG rod is coated on its ends to define an optical resonator containing the YAG rod. The YAG rod is made sufficiently short, i.e., 1 mm, so that it will support only two axial resonant (lasing) modes. The rod is transversely stressed to polarize the two original modes and to excite a third lasing mode orthogonally polarized to the first two modes. The third mode is separated from the first two modes to provide stable, single mode TEM.sub.001 output. The transverse stress is applied by means of a spring clamp made of a material, Be-Cu, having a low temperature coefficient.