Abstract: A longitudinally pumped laser including a pumping module having a pumped light source and an input optic, and a resonator having a first reflecting surface serving as an input mirror, a laser medium and a second reflecting surface serving as an output mirror. In order to avoid impairment of the operation of the pumped light source by retroreflected pumped light and/or by leakage radiation from the resonator, without appreciably worsening the adaptation of the pumped light ray to the mode volume of the laser, the pumping module and the resonator are so disposed relative to each other that a first optical axis defined by the pumped light source and input optic defines with a second optical axis defined by the resonator a predetermined angle of intersection greater than 0.degree. and less than about 15.degree., and more preferably in the range of about 0.05.degree. and about 1.degree..

Abstract: In order to produce higher harmonics more efficiently in a laser having a first optically nonlinear crystal acting as a frequency doubler, and at least one further optically nonlinear crystal acting as a frequency multiplier disposed behind the first nonlinear crystal in the direction of propagation of laser radiation produced by the laser, the first to second-to-last optically nonlinear crystals are selected to each have a walk-off angle in the range of 0.1.degree. to 6.degree., and all of the optically nonlinear crystals are disposed relative to one another in such a way that the plane of the principal section of one crystal contains a direction of small angular acceptance with respect to phase matching of a following crystal.

Abstract: A frequency-doubled laser contains laser diodes as a pumped light source and a resonator (R) comprising in the stated order a first mirror (5), a laser medium (6), a Brewster plate (7) as a polarizer, a nonlinear crystal (8) for frequency doubling and a plane mirror (9) as an output mirror. The plane mirror ensures that shifts of rays taking place within the nonlinear crystal remain in the radiation area even when returning through the crystal, in contrast to the prior art which uses a concave mirror as an output mirror that causes shifted rays from the nonlinear crystal to be deflected out of the beam path. The inventive measure achieves a laser light that has high efficiency and is virtually free from intensity fluctuations.

Abstract: A solid state type laser contains a laser rod (1) and at least one pumping module (2d, 2e) equipped with laser diodes (D) which is designed as a ring-shaped or partial ring-shaped module with a circumferential cooling duct (4). This geometry permits the lost heat of the laser diodes (D) to be effectively removed radially outward through the cooling duct (4), on the one hand, and through thermal conduction in the material of the module, on the other hand. The individual laser diodes are so arranged that the major axis of each rotationally non-symmetrical lobe of laser light, along which axis the main radiation power from the respective laser diode is obtained, lies in a plane substantially parallel to the longitudinal axis of the laser rod.