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: A diode-pumped solid state laser for single-mode operation contains a resonator with an input mirror and an output mirror between which an active laser medium, a polarizer and a birefringent crystal are disposed. The crystal is disposed with its optical axes in such a way that the latter form an angle of 45.degree. to the polarizing direction produced by the polarizer. The losses for the ordinary and extraordinary rays are adjusted to be substantially equal. A temperature control means is used to keep the temperature of the birefringent crystal at a constant value so that the refractive indices and the length of the crystal do not change.

Abstract: To produce blue light by means of a laser, pumped light is coupled into a birefringent, nonlinear crystal (5) in a variable frequency laser (1) from a laser diode pumped light source (7, 8, 9) via an input mirror (3). Due to adjustment of the inclination of the crystal (5) or with the aid of tempering means (6) for the crystal, most of the pumped light is absorbed in the crystal (5)--upon suitable polarization of the pumped light--while the rest is available for a frequency mixture of the fundamental Wave of the laser and of the pumped light. Via an output mirror (4) blue laser light with a Wavelength of e.g. 459 nm is coupled out, with a fundamental wave of e.g. 1064 nm and pumped light with a wavelength of e.g. 806 nm.

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.