Passively Q-switched lasers and short wave infrared (SWIR) electro-optical systems including such lasers. A passively Q-switched laser may include a gain medium (GM) having a stimulated emission cross section σ.sub.SE, a saturable absorber (SA) having an absorption cross section (σ.sub.a) which is less than three times the σ.sub.SE of the GM, and an optical resonator within which the GM and the SA are positioned, the optical resonator comprising a high reflectivity mirror and an output coupler, wherein at least one of the high reflectivity mirror and the output coupler comprises a curved mirror, directing light within the optical resonator such that an effective cross-section of a laser mode within the SA (A.sub.SA) is smaller than a cross-section of a laser mode within a Rayleigh length of the pump (A.sub.GM).

An electrodeless laser-driven light source includes a laser that generates a CW sustaining light. A pump laser generates pump light. A Q-switched laser crystal receives the pump light generated by the pump laser and generates pulsed laser light at an output in response to the generated pump light. A first optical element projects the pulsed laser light along a first axis to a breakdown region in a gas-filled bulb comprising an ionizing gas. A second optical element projects the CW sustaining light along a second axis to a CW plasma region in the gas-filled bulb comprising the ionizing gas. A detector detects plasma light generated by a CW plasma and generates a detection signal at an output. A controller generates control signals that control the pump light to the Q-switched laser crystal so as to extinguish the pulsed laser light within a time delay after the detection signal exceeds a threshold level.

In one embodiment, a lidar system includes a pump laser configured to produce pulses of light at a pump wavelength. The lidar system further includes an optical parametric oscillator (OPO) with an OPO medium configured to: receive the pump pulses from the pump laser; convert at least part of the received pump pulses into pulses of light at a signal wavelength and pulses of light at an idler wavelength; and emit at least a portion of the signal pulses. The lidar system also includes a scanner configured to scan the emitted pulses of light across a field of regard and a receiver configured to detect at least a portion of the scanned pulses of light scattered by a target located a distance from the lidar system. The lidar system also includes a processor configured to determine the distance from the lidar system to the target.

In one embodiment, a lidar system includes a Q-switched laser configured to emit pulses of light, where the Q-switched laser includes a gain medium and a Q-switch. The lidar system further includes a scanner configured to scan the emitted pulses of light across a field of regard and a receiver configured to detect at least a portion of the scanned pulses of light scattered by a target located a distance from the lidar system. The lidar system also includes a processor configured to determine the distance from the lidar system to the target based at least in part on a round-trip time of flight for an emitted pulse of light to travel from the lidar system to the target and back to the lidar system.

A compact laser is provided for in accordance with an exemplary embodiment in the present disclosure includes a compact resonator structure using a non-planar geometry of bulk components. The laser includes a preferred rotational direction of lasing modes and employs bulk components for establishing the preferred rotational direction of lasing modes within resonator. In some embodiments, the preferred rotational direction of lasing modes is established using a reflective element that is outside the resonator structure. In some embodiments, the reflective element induces polarization shifts in the reflected light that are compensated for by a wave plate, which may be outside the resonator structure.

A radial polarization disk laser, including a pumping source, a collimator lens, a focusing lens, a laser gain medium, a Brewster axial cone, and a output lens, which are sequentially arranged along a laser light path. An angle formed between the conical surface and the bottom surface of said Brewster axial cone is a Brewster's angle. Said laser gain medium is bonded with said bottom surface; said laser gain medium and said output lens form a laser harmonic oscillator cavity therebetween. The pumped laser light emitted by said pumping source passes through said collimator lens and said focusing lens, then is focused on the laser gain medium, and. the generated photons oscillate in said laser harmonic oscillator cavity, and then a radial polarized laser beam is finally output by said output lens.

A light concentrator includes a luminescent concentrator and a gain medium. The luminescent concentrator includes a semiconductor material and the semiconductor material absorbs first photons. The first photons have energy greater than or equal to a threshold energy, and the semiconductor material emits second photons through a spontaneous emission process where the second photons have less energy than the first photons. The gain medium is optically coupled to the luminescent concentrator to receive the second photons. The gain medium absorbs the second photons, and in response to absorbing the second photons, the gain medium emits third photons through a stimulated emission process. The third photons have less energy than the second photons.

A light source unit, a light source module, and a laser ignition device. The light source unit includes a lens array including a plurality of two-dimensionally disposed lenses and a lens substrate portion that supports the lenses, and an element substrate portion that supports a plurality of light emitters. The element substrate portion has a second coefficient of linear expansion. The first coefficient of linear expansion is approximately same as the second coefficient of linear expansion of the element substrate portion. The light source module includes the light source unit, and a condenser lens to collect and condense pump light emitted from the light source unit. The laser ignition device includes the light source module, and a laser resonator to absorb the pump light emitted from the light source unit.

A method for manufacturing an optical element is a method for manufacturing an optical element in which laser light is transmitted, reciprocated, or reflected, and the method includes a first step of obtaining a bonded element formed by subjecting a first element part and a second element part, both being transparent to laser light, to surface activated bonding with a non-crystalline layer interposed therebetween; and after the first step, a second step of crystallizing at least a portion of the non-crystalline layer by raising the temperature of the bonded element. In the second step, the temperature of the bonded element is raised to a predetermined temperature that is lower than the melting points of the first element part and the second element part.

The laser cavity is of the unstable type and is provided with a passive Q-switch, the passive Q-switch comprising a saturable absorber that has an absorption gradient, so that the absorption profile of the saturable absorber is inhomogeneous over the cross section of the beam travelling in the laser cavity.