To address the need to excite lasers at a high frequency while minimizing electrical parasitic components, the present invention embraces a system and method of exciting a laser using a direct injection of an electron beam. The system may include a low voltage electron emission device made of one or more electron sources. When the device is activated, an electrical field is applied to the tip of each electron source, causing the electron source to emit a stream of electrons. The electrons are directed into a VCSEL, causing it to emit an optical signal. In another aspect, a system for random number generation is provided. The system may also include a processor that receives a measurement of an initial random value, executes an algorithm, where at least one input of the algorithm is the initial random value, and determines a final random value.

A topological bulk laser includes a topological photonic crystal (32) having an energy band inversion between dipole mode and quadrupole mode near the center of Brillouin zone and a trivial photonic crystal (31) not having band inversion for splicing to each other. The reflection and confinement of an optical field occurs at the interface; and the interface encloses to form a closed contour, thereby forming a laser cavity with an effective cavity feedback for lasing at the interior of the interface. This band-inversion-induced reflection mechanism induces single-mode lasing with directional vertical emission. At room temperature, the topological bulk laser can achieve low threshold, narrow linewidth, and a high side-mode suppression ratio, reduce the fabrication difficulty and costs, and improve heat dissipation and electrical injection efficiency, hence improving lifetime and stability of devices.

A collinear T-cavity VECSEL system generating intracavity Hermite-Gaussian modes at multiple wavelengths, configured to vary each of these wavelengths individually and independently. A mode converter element and/or an astigmatic mode converter is/are aligned intracavity to reversibly convert the Gaussian modes to HG modes to Laguerre-Gaussian modes, the latter forming the system output having any of the wavelengths provided by the spectrum resulting from nonlinear frequency-mixing intracavity (including generation of UV, visible, mid-IR light). The laser system delivers Watt-level output power in tunable high-order transverse mode distribution.

Disclosed here are methods, devices, and systems for generating an output light beam for a pulsed laser. An example method may comprise generating one or more pump optical beams comprising at least two photons having a pump wavelength. A first nonlinear stage may convert the at least two photons to a first photon having a first wavelength that is half of the pump wavelength. The first optical beam may be caused to spatially overlap with a seed optical beam. At least two second nonlinear stages separated by a gap may be used to convert, based on the seed optical beam, the first photon to a second photon having a second wavelength and a third photon having a target wavelength greater than the pump wavelength. A third nonlinear stage may convert the second photon to a fourth photon and a fifth photon each having the target wavelength or having a wavelength within an offset range of the target wavelength.

A visible light source includes a substrate, a vertical-cavity surface-emitting laser including an active semiconductor region configured to emit infrared light and a first reflector configured to reflect the infrared light emitted by the active semiconductor region, a second reflector configured to reflect the infrared light and form a vertical cavity for the infrared light with the first reflector, and one or more micro-resonators configured to receive the infrared light and generate visible light in one or more colors using the infrared light through optical parametric oscillation. The visible light source also includes one or more output couplers configured to couple the visible light in one or more colors from the one or more micro-resonators into free space or into a photonic integrated circuit.

A laser system produces pulses having wavelengths between 2000 nm and 2100 nm, peak output powers greater than 1 kW, average powers greater than 10 W, pulse widths variable from 0.5 to 10 nsec, pulse repetition frequencies variable from 0.1 to over 2 MHz, and a pulse extinction of at least 60 dB. Pulses from a diode laser having a wavelength between 1000 nm and 1100 nm are amplified by at least one fiberoptic amplifier and applied as the pump input to an Optical Parametric Amplifier (OPA). A cw laser provides an OPA seed input at a wavelength between 2000 nm and 2200 nm. The idler output of the OPA having difference frequency wavelength between 2000 nm and 2100 nm is further amplified by a crystal amplifier. The fiberoptic amplifier can include Ytterbium-doped fiberoptic. The crystal amplifier can include a Ho:YAG, Ho:YLF, Ho:LuAG, and/or a Ho:Lu2O3 crystal.

A narrow linewidth mid infrared laser, including a pumping laser diode with a fast-axis compressor and a pumping wavelength λ.sub.o; and an optical resonator arranged to receive the pumping wavelength λ.sub.o, the optical resonator including a laser crystal with a lasing wavelength λ.sub.p, a dichroic mirror, and a nonlinear crystal to generate an idler wavelength λ.sub.i.

A vehicle component, and a method and tool for forming the component are provided. First and second tools with first and second surfaces, respectively, are provided. The first tool is translated along a first axis towards the second tool such that the first and second surfaces cooperate to define a mold cavity configured to form an accessory mount feature with an aperture. The second surface is configured to form an integrated rib extending outwardly from an upper surface of the mount feature to a planar bearing surface surrounding the aperture with the planar bearing surface oriented at an acute angle relative to the upper surface. The first axis is substantially parallel to the upper surface.

The present invention describes a laser system for eliminating astigmatism to produce an elliptical laser beam that has an ellipticity between about 0.9 to 1.0. The laser system described herein allows for increased conversion efficiency and output powers. on-linear optical elements in the laser system eliminate astigmatism. The laser system comprises one or more cavities with wavelength splitters that act as dual-minor chambers for single-pass light transmission through the non-linear optical elements to reduce cavity size or as beam splitters for double-pass light transmission through the non-linear optical elements to increase laser output power. The laser system may also include a birefringent filter and/or etalon in the first cavity for polarization and wavelength tuning. The laser system may also generate a high-power, deep-ultraviolet laser output. The laser system may also be devoid of curved mirrors and non-normal incidence reflection to eliminate astigmatism.

A passively Q-switched laser with intracavity pumping is described. The passively Q-switched laser has an optically pumped gain element and a saturable absorber element. The optically pumped gain element is situated in an extended cavity of a VECSEL (Vertical Extended Cavity Surface Emitting Laser) so that the gain element is pumped by a circulating pump beam of the VECSEL. The passively Q-switched laser may produce output pulses at an eye-safe wavelength using a low gain laser transition and may use a plurality of surface emitting gain regions to pump the passively Q-switched laser.