Abstract: Disclosed is a system and method for remote sensing, surface profiling, object identification, and aiming based on two-photon population inversion and subsequent photon backscattering enhanced by superradiance using two co-propagating pump waves. The present disclosure enables efficient and highly-directional photon backscattering by generating the pump waves in properly pulsed time-frequency modes, proper spatial modes, with proper group-velocity difference in air. The pump waves are relatively delayed in a tunable pulse delay device and launched to free space along a desirable direction using a laser-pointing device. When the pump waves overlap in air, signal photons will be created through two-photon driven superradiant backscattering if target gas molecules are present. The backscattered signal photons propagate back, picked using optical filters, and detected.

Abstract: In some embodiments, a field effect transistor structure includes a first semiconductor structure and a gate structure. The first semiconductor structure includes a channel region, and a source region and a drain region. The source region and the drain region are formed on opposite ends of the channel region, respectively. The gate structure includes a central region and footing regions. The central region is formed over the first semiconductor structure. The footing regions are formed on opposite sides of the central region and along where the central region is adjacent to the first semiconductor structure.

Abstract: In fabricating a semiconductor structure, a group IV substrate and a group III-V chiplet are provided. The group III-V chiplet is bonded to the group IV substrate, and patterned to produce a patterned group III-V device. A blanket dielectric layer is formed over the patterned group III-V device. A first contact hole is formed in the blanket dielectric layer over a first portion of the patterned group III-V device. A first liner stack and a first filler metal are subsequently formed in the first contact hole. A second contact hole is formed in the blanket dielectric layer over a second portion of the patterned group III-V device. A second liner stack and a second filler metal are subsequently formed in the second contact hole. A first bottom metal liner of the first liner stack can be different from a second bottom metal liner of the second liner stack.

Abstract: A laser system may include a seed laser formed from a Ti:Sapphire laser providing pulsed light and an optical parametric amplifier to generate pulsed light within a Holmium emission spectrum as seed pulses in response to the pulsed light from the Ti:Sapphire laser. A laser system may further include an amplifier to generate amplified pulses of light in response to the seed pulses from the seed laser, where the amplified pulses include at least some of the seed pulses amplified by the one or more Holmium-doped gain media pumped by the one or more pump lasers. The amplifier may include one or more Holmium-doped gain media and one or more pump lasers providing continuous-wave pump light within an absorption spectrum of the one or more Holmium-doped gain media.

Abstract: A diamond Raman laser may include a diamond Raman oscillator (DRO) with a first diamond gain medium, a seed laser providing a seed beam at a seed wavelength, and a cavity configured to resonate at a first-Stokes wavelength, the first-Stokes wavelength corresponding to first-Stokes emission in diamond when pumped with the seed wavelength, and where the DRO outputs a first-Stokes beam at the first-Stokes wavelength. The diamond Raman laser may further include a diamond Raman amplifier (DRA) to amplify the first-Stokes beam and generate an amplified first-Stokes beam, where the DRA includes two or more diamond Raman amplification stages, each including one or more second diamond gain media, and one or more optical filters to filter light with a second-Stokes wavelength generated in at least one of the one or more second gain media.

Abstract: A circuit includes a laser diode and a switched-capacitance charge pump coupled to control the laser diode. The charge pump can include a capacitor and a switching circuit that is capable of triggering a charge and discharge of the capacitor. The switching circuit can include a switch and an inverting circuit.

Abstract: In an example, a tandem pumped fiber amplifier may include a seed laser, one or more diode pumps, and a single or plural active core fiber. The single or plural active core fiber may include a first section to operate as an oscillator and a second different section to operate as a power amplifier. The one or more diode pumps may be optically coupled to the first section of the single or plural active core fiber, and the seed laser may be optically coupled to the single active core or an innermost core of the plural active core fiber.

Abstract: The invention relates to an apparatus for generating laser pulses. It is an object of the invention to provide a method for generating synchronized laser pulse trains at variable wavelengths (e.g., for coherent Raman spectroscopy/microscopy), wherein the switching time for switching between different wavelengths should be in the sub-?s range. For this purpose the apparatus according to the invention comprises a pump laser (1), which emits pulsed laser radiation at a specified wavelength, an FDML laser (3), which emits continuous wave laser radiation at a cyclically variable wavelength, and a nonlinear conversion medium (4), in which the pulsed laser radiation of the pump laser (1) and the continuous wave laser radiation of the FDML laser (3) are superposed.

Abstract: A light source package structure is provided. The light source package structure includes a substrate, an upper electrode layer, a light emitting unit, a photodiode, a surrounding wall, a light permeable element, and a coating layer. The substrate includes a first surface and a second surface that is opposite to the first surface. The upper electrode layer is disposed on the first surface of the substrate. The light emitting unit and the photodiode both are disposed on the upper electrode layer. The surrounding wall is disposed on the first surface and is arranged to surround the light emitting unit and the photodiode. The light permeable element is disposed on the surrounding wall. The coating layer is disposed inside of the surrounding wall and is coated on a part of the first surface and a part of the upper electrode layer.

Abstract: Processes and apparatuses described herein provide for an efficient cyclical fiber-optic connection between a source component and multiple destination components in a computing environment. A comb laser generates a laser signal that includes laser light of a first frequency that is red-shifted from a carrier frequency. The comb laser concurrently transmits the laser signal to four ring resonators via an optical waveguide. Three of the ring resonators are initially configured for optical resonance at a second frequency that is blue-shifted from the carrier frequency, while one of the ring resonators is initially configured for optical resonance at the first frequency. The laser signal is modulated to communicate data to a first target location associated with the ring resonator that is initially configured for optical resonance at the first frequency.

Abstract: The present invention provides a method for estimating a condition parameter of a laser diode having an associated photodiode, to an apparatus for monitoring the operation of such a laser diode, and to a particle sensor apparatus. The photodiode (PD) is operable together with the laser diode (LD), wherein it detects the light (LS) of the laser diode (LD) and converts it into an electrical current, and is thermally coupled to the laser diode (LD). The at least one condition parameter is estimated during the operation of the laser diode (LD) and the estimation is based on current measurements and/or voltage measurements at the laser diode (LD) and/or at the photodiode (PD).

Abstract: In a light source module A, a lens shapes emitted light 1a of a semiconductor laser. A plate on which the lens is disposed has a through hole through which the emitted light of the semiconductor laser passes and an adjustment surface that is used for adjusting the position of the lens with respect to the through hole in a direction perpendicular to the optical axis L of the semiconductor laser. An end surface 5b of the lens that is opposite to an optical light-emitting surface of the lens is fixed to the adjustment surface with an adhesive AD. A stepped portion that is recessed in the direction of the optical axis L is formed in a bonding portion in which the end surface of the lens and the adjustment surface are bonded together.

Abstract: Examples of the present disclosure include a tunable laser comprising a waveguide including gain section. The waveguide overlies and is optically coupled to another waveguide. The another waveguide has a reflector at one end. A laser cavity is formed in the waveguides.

Abstract: A gallium and nitrogen containing laser diode device. The device has a gallium and nitrogen containing substrate material comprising a surface region. The surface region is configured on either a non-polar crystal orientation or a semi-polar crystal orientation. The device has a recessed region formed within a second region of the substrate material, the second region being between a first region and a third region. The recessed region is configured to block a plurality of defects from migrating from the first region to the third region. The device has an epitaxially formed gallium and nitrogen containing region formed overlying the third region. The epitaxially formed gallium and nitrogen containing region is substantially free from defects migrating from the first region and an active region formed overlying the third region.

Abstract: A laser diode is provided, including at least a defect blocking layer deposited between the GaAs substrate and the active layer, so that the crystal defects of the GaAs substrate can be blocked or reduced from propagation to the active layer when the epitaxial layer is formed on the GaAs substrate. As such, the crystal quality of the active layer can be improved, thereby improving the reliability and optical property of the laser diode.

Abstract: A light emitting device includes a base having a bottom part, a first semiconductor laser element disposed on the bottom part of the base, and a first light reflecting member disposed on the bottom part of the base. The first light reflecting member has a light reflecting surface configured to reflect light emitted from the first semiconductor laser element. The light reflecting surface of the first light reflecting member is a curved surface configured such that, with respect to the major portion of the light emitted from the first semiconductor laser element, the beam divergence angle of the light reflected by the light reflecting surface is greater than zero and smaller than the beam divergence angle of the light irradiating the light reflecting surface.

Abstract: A laser diode bar: includes a semiconductor substrate comprising a first semiconductor layer of a first conductivity type; a first laser diode stack on an upper side of the semiconductor layer; a second laser diode stack on the upper side of the semiconductor layer, the second laser diode stack being electrically connected in series with the first laser diode stack, in which an electrical conductivity of the first semiconductor layer of the first conductivity type is higher than an electrical conductivity of each semiconductor layer of the first and second laser diode stacks; and a first electrode layer on the first laser diode stack, in which the first electrode layer electrically connects the first laser diode stack to a portion of the first semiconductor layer of the first conductivity type that is between the first laser diode stack and the second laser diode stack.

Abstract: Laser diode technology incorporating etched facet mirror formation and optical coating techniques for reflectivity modification to enable ultra-high catastrophic optical mirror damage thresholds for high power laser diodes.

Abstract: Optical devices and methods of manufacturing and operating such optical devices. In an embodiment, an optical device includes a substrate, a multi-layer structure having a first surface in contact with a first surface of the substrate, a first mirror disposed over a second surface of the multi-layer structure, a second mirror disposed over a second surface of the substrate, an intermediate mirror within the multi-layer structure, and an optical gain structure within the multi-layer structure. The device may include a first optically resonant cavity within the multi-layer structure, bounded by the first mirror and the intermediate mirror, where the first optically resonant cavity includes the optical gain structure. The device may further include a second optically resonant cavity, bounded by the first and second mirrors, where the second optically resonant cavity includes the first optically resonant cavity, the second optically reflective layer, and the substrate.

Abstract: A light based treatment device comprises an optical arrangement at a light exit end of an optical fiber. The optical arrangement includes a master oscillator power amplifier based on a semiconductor optical laser and a crystal optical amplifier. In this way, the peak power provided along the optical fiber can be reduced to prevent damage to the optical fiber, while enabling a sufficiently high pulse power to be delivered for tissue treatment.