Abstract: A surface emitting laser (SEL) with an integrated absorber. A lower mirror and an output coupler define a laser cavity of the SEL. A monolithic gain structure positioned in the laser cavity includes a gain region and an absorber, wherein a saturation fluence of the absorber is less than a saturation fluence of the gain region.

Abstract: A passively mode-locked solid-state laser is designed to emit a continuous-wave train (51, 52) of electromagnetic-radiation pulses, the fundamental repetition rate of the emitted pulses exceeding 1 GHz, without Q-switching instabilities. The laser includes an optical resonator (3.1), a solid-state laser gain element (2) placed inside the optical resonator (3.1), a device (1) for exciting said laser gain element (2) to emit electromagnetic radiation having the effective wavelength, and a device (4) for passive mode locking including a saturable absorber. The laser gain element (2) is a laser material with a stimulated emission cross section exceeding 0.8×10?18 cm2 at the effective wavelength, and is made of Nd:vanadate. The saturable absorber (4) is preferably a semiconductor saturable absorber mirror (SESAM) device. Even higher repetition rates are achieved by operating the laser in the soliton regime. For use in fiber-optical telecommunication, the laser wavelength is preferably shifted to 1.

Abstract: A pulsed solid-state thin-disk laser comprises an optical resonator and a solid-state laser gain medium placed inside the optical resonator. The laser gain medium is in the shape of a thin plate or layer with two end faces, the extension of the end faces being greater than a thickness of said plate or layer measured in a direction perpendicular to one of the end faces. One of the end faces comprises a cooling surface, via which the laser gain medium is cooled. A pumping source is provided for exciting the laser gain medium to emit electromagnetic radiation. The thin-disk laser further comprises means for passive mode locking placed inside the optical resonator. The mode-locking means are preferably a semiconductor saturable absorber mirror (SESAM). The laser offers a high average power, a good beam quality, short pulses and a high efficiency. Problems such as thermal lensing, Q-switching instabilities and damages of the mode-locking means are avoided. Moreover, the output power of the laser is scalable, i.e.

Abstract: A passively mode-locked optically pumped semiconductor vertical-external-cavity surface-emitting laser (OPS-EXSEL) is disclosed. The laser is mode locked by a semiconductor saturable absorber mirror (SESAM) which forms part of an external cavity. Both the beam-quality limitations of edge-emitting lasers, and the power restrictions of electrically pumped surface-emitting lasers are overcome. The laser uses a semiconductor wafer in which a stack of quantum wells is grown adjacent to a single Bragg-mirror structure. Light from one or more multi-mode high-power diode lasers is focused onto the face of the wafer and pumps the wells by absorption in the barrier regions. The area of the laser mode on the active mirror can be about 104 times larger than the mode area on the facet of an edge-emitting laser, offering scope for the generation of high average power and large pulse energy. At the same time the external cavity enforces fundamental mode operation in a circular, near-diffraction-limited beam.