Abstract: A transient voltage suppressor with adjustable trigger and holding voltages is provided, including a heavily doped substrate of a first conductivity type connected to a first node, a lightly doped epitaxial layer of a second conductivity type on the substrate, a first and third well region of the first conductivity type, a second well region of the second conductivity type, a first and third heavily doped region of the second conductivity type and a second heavily doped region of the first conductivity type. The heavily doped regions are commonly electrically connected to a second node, and individually disposed in the well regions. Trenches are disposed opposite in the substrate for electrical isolation. A floating base bipolar junction transistor and silicon controlled rectifier can be respectively formed under a positive and negative surged mode. Accordingly, the invention is advantageous of superior electrical performances, high layout flexibility and low area consumption.

Abstract: A controller stabilizes a distributed feedback plus reflection (DFB+R) laser, which has a back facet, a DFB section, a passive section, and a front facet with a low reflective element. An etalon filter is formed by a portion of the DFB section, the passive section, and the low reflective element. Control circuitry directly modulates the DFB section with a modulation signal and biases the passive section with a bias signal. In operation, a lasing mode of the DFB section is aligned to a long wavelength edge of one of the periodic peaks of a reflection profile of the etalon filter. Meanwhile, photodiodes are arranged to monitor the output power emitted from the laser's front and back facets. The control circuitry monitors a ratio of the detected output power and adjusts the bias based on the monitored ratio.

Abstract: According to various embodiments, a system for stabilizing operation of semiconductor laser frequency combs via optical feedback is disclosed. The system includes an external cavity having a beam-splitter, polarizer, and mirror or partially reflective element mounted on a translational stage. The external cavity and a laser facet of the semiconductor laser form an external optical resonator for coupling light to a laser cavity.

Abstract: A display device includes: a display panel including: a substrate; a light-emitting layer on a first surface of the substrate; and wire pads on the first surface of the substrate, and adjacent to a side of the substrate; and a support member on a second surface of the substrate opposite to the first surface of the substrate. The substrate includes stepped portions protruding from the second surface in a thickness direction of the substrate, and the stepped portions overlap with the wire pads.

Abstract: An electronic device includes a substrate, a circuit layer disposed on the substrate and including a plurality of insulating layers, a plurality of conductive layers, and at least one semiconductor layer, a light emitting element layer disposed on the circuit layer and including a light emitting element, an encapsulation layer disposed on the light emitting element layer, and a sensor layer disposed on the encapsulation layer and including a plurality of sensor conductive layers. A first layer of the conductive layers, the at least one semiconductor layer, and the sensor conductive layers includes a first sensor, a second layer different from the first layer of the conductive layers, the at least one semiconductor layer, and the sensor conductive layers includes a second sensor, and the first sensor and the second sensor overlap a second area.

Abstract: A driver circuit may include an optical emitter. The driver circuit may include a first switch that, in a closed state, is to cause charging of an inductive element, and when transitioning from the closed state to an open state is to cause discharging of the inductive element to charge a capacitive element. The driver circuit may include a second switch that in a closed state is to cause discharging of the capacitive element to provide an electrical pulse to the optical emitter. The driver circuit may include a signal generator configured to generate a first signal for controlling the open state and the closed state of the first switch, and a pulse shortening element configured to shorten a pulse width of the first signal to generate a second signal for controlling the open state and the closed state of the second switch.

Abstract: An optical assembly reduces a spectral bandwidth of an output beam of a laser. The assembly includes a beam-expanding optical unit within a laser resonator. The latter serves to increase a beam cross section of a resonator-internal laser beam in at least one expansion cross-sectional dimension such that at least one resonator-internal expansion laser beam section arises. The assembly also includes an optical grating in a retroreflective arrangement for the resonator-internal laser beam. A beam-limiting stop acts in the expansion cross-sectional dimension and is arranged in the beam path of the expansion laser beam section. This yields an optical assembly in which unwanted thermal effects on account of optical components of the optical assembly heating during laser operation due to a local power density of the resonator-internal laser beam are reduced or avoided.

Abstract: A vertical cavity surface emitting device includes a substrate, a first multilayer film reflecting mirror, a light-emitting structure layer with a light-emitting layer, and a second multilayer film reflecting mirror. The second multilayer film reflecting mirror constitutes a resonator between the first and second multilayer film reflecting mirrors. The second multilayer film reflecting mirror includes a first multilayer film, an intermediate film, and a second multilayer film. The first and second multilayer films have low refractive index films and high refractive index films that are alternately stacked. The intermediate film covers an upper surface of the first multilayer film and film has a translucency to a light emitted from the light-emitting layer. The second multilayer film partially covers an upper surface of the intermediate film. The intermediate film has a film thickness based on ½ of a wavelength inside the intermediate film of light emitted from the light-emitting layer.

Abstract: A light-emission device includes: a first light emitting element chip; a second light emitting element chip having a light output higher than a light output of the first light emitting element chip, the second light emitting element chip being configured to be driven independently from the first light emitting element chip and arranged side by side with the first light emitting element chip; and a light diffusion member including a first region provided on an emission path of the first light emitting element chip and a second region provided on an emission path of the second light emitting element chip, and having a diffusion angle at the second region larger than a diffusion angle at the first region.

Abstract: A control method for stabilizing excimer laser pulse energy includes: obtaining a measured energy value of the n-th pulse in a pulse sequence; calculating the difference between the measured energy value and the preset energy value; taking the z-th pulse of the sequence as a demarcation point, when n is a positive integer less than z, the discharge voltage value of the next pulse is calculated according to a first mathematical model, and when n is an integer greater than z?1, the discharge voltage value of the next pulse is calculated according to a second mathematical model; and the next pulse is generated according to the discharge voltage value. A control system based on the control method includes: a high-voltage discharge module, a laser cavity, a laser parameter measurement module, and an energy stability controller.

Abstract: A laser system having an optical ring resonator, a beam splitter that directs a first beam travelling in a first direction around the ring resonator, out of the resonator towards a reflector that reflects the first beam back into the resonator to travel in an opposite direction around the optical ring resonator that is in the same direction as a second beam travelling around the optical ring resonator; and a beam modifier configured and adapted to modify a spatial distribution of phase across an aperture of the first beam such as to cause it to become more similar or substantially match that of a spatial distribution of phase across an aperture of the second beam.

Abstract: Within examples, a laser includes a first electrode and a second electrode; a first transport layer and a second transport layer that are between the first electrode and the second electrode; a gain layer positioned between the first transport layer and the second transport layer, where the gain layer comprises a material having a Perovskite crystal structure; and a substrate on which the first electrode, the second electrode, the first transport layer, the second transport layer, and the gain layer are formed, where a distributed feedback (DFB) waveguide is formed within the first transport layer, and where the laser is configured such that a current flowing through the gain layer between the first electrode and the second electrode causes the gain layer to emit coherent light. Examples also include methods for fabricating the laser, as well as additional lasers and methods for forming those lasers.

Abstract: A VCSEL/VECSEL array design is disclosed that results in arrays that can be directly soldered to a PCB using conventional surface-mount assembly and soldering techniques for mass production. The completed VCSEL array does not need a separate package and no precision sub-mount and flip-chip bonding processes are required. The design allows for on-wafer probing of the completed arrays prior to singulation of the die from the wafer. Embodiments relate to semiconductor devices, and more particularly to multibeam arrays of semiconductor lasers for high power and high frequency applications and methods of making and using the same.

Abstract: Pulsed laser drivers are disclosed comprising Gallium Nitride (GaN) power transistors for driving diode laser systems requiring high current and fast pulses, such as laser drivers for LIDAR (Light Detection and Ranging) systems. Drivers are capable of delivering pulses with peak current ?100 A, e.g. 170 A to provide high peak power, fast pulses with nanosecond rise times and nanosecond pulse duration, for driving multi-channel laser diode arrays with 40 A per channel for 120 W output per channel for a combined peak output of 480 W. For lower duty cycle, example driver circuits are disclosed comprising a high current power transistor for direct drive with drive assist. For higher duty cycle, example resonant driver circuits are disclosed comprising two high current power transistors. Implementation of resonant driver circuits with GaN technology provides fast charging for short pulse operation at higher repetition rates or for pulse code modulation.

Abstract: A printed circuit board according to an embodiment comprises: a substrate comprising at least two insulating layers; pads arranged on the substrate; heat dissipation vias arranged to pass through the substrate in a region of the substrate which vertically overlaps the pads; and through vias arranged to pass through the substrate in a region of the substrate which does not vertically overlap the pads, wherein each heat dissipation via includes a plurality of via parts which are spaced apart from each other in at least one of the at least two insulating layers, the upper surface of each of the plurality of via parts has a first horizontal width in a first direction that is smaller than a second horizontal width thereof in a second direction different from the first direction, and the plurality of via parts have a surface area corresponding to 10% or greater of the surface area of the pads.

Abstract: A method of producing an ultraviolet laser diode with a low oscillation threshold current density includes stacking a first cladding layer, a light-emitting layer, and a second cladding layer on a substrate in this order to form a nitride semiconductor laminate (step S101), etching at least a portion of the nitride semiconductor laminate to form a mesa structure and setting the ratio between the length of the resonator end faces and the length of the side surfaces of the mesa structure in plan view between 1:5 and 1:500 (step S102), disposing first conductive material on a portion of a first area and applying heat treatment of 400° C. or higher to form a first electrode (step S103), and disposing a second conductive material in an area on the second cladding layer, at a distance of 5 ?m or more from the side surfaces, to form a second electrode (step S104).

Abstract: Disclosed is a semiconductor laser with a substrate mode suppression layer, comprising a substrate, a first limiting layer, a first waveguide layer, an active layer, a second waveguide layer, an electron blocking layer, and a second limiting layer sequentially stacked from bottom to top. A Si/C concentration ratio of an element Si to an element C of the substrate mode suppression layer?that of the first sub-limiting layer?that of the second sub-limiting layer. An In/Al concentration ratio of an element In to an element Al of the substrate mode suppression layer?that of the first sub-limiting layer?that of the second sub-limiting layer. An H/C concentration ratio of an element H to an element C of the substrate mode suppression layer?that of the second sub-limiting layer?that of the first sub-limiting layer.

Abstract: A vertical cavity surface emitting laser (VCSEL) may include an active region (e.g., one or more quantum wells) and a chirped pattern reflector. The active region may be configured to be electrically pumped such that the active region generates light having a fundamental mode and a higher order mode. The chirped pattern reflector may include a first portion presenting to the active region as a first portion of an effective mirror having a concave shape and a second portion presenting to the active region as a second portion of the effective mirror having a convex shape.

Abstract: A semiconductor laser comprising a single mode laser cavity having a stack of semiconducting layers defining a transversal p-n junction is provided. A plurality of electrodes are coupled to corresponding sections of the laser cavity along the longitudinal light propagation direction, each corresponding section defining one of an amplification section or a modulation section. One or more DC sources are coupled to the electrodes associated with the amplification sections to forward-bias the p-n junction above transparency, so as to provide gain in the associated amplification sections. One or more modulation signal sources are coupled to the electrodes associated with the modulation sections, and apply a modulation signal across the p-n junction below transparency, the modulation signal providing a modulation of an output optical frequency of the semiconductor laser. Each modulation section is operated in photovoltaic mode.

Abstract: A semiconductor laser device A1 comprises a semiconductor laser chip 2 and a stem 1. The stem 1 includes a base 11 and leads 3A, 3B, and 3C fixed to the base, and supports the semiconductor laser chip 2. The semiconductor laser device A1 further comprises a first metal layer 15 including a first layer 151 covering the base 11 and the leads 3A, 3B, and 3C, a second layer 152 interposed between the first layer 151 and each of the base 11 and the leads 3A, 3B, and 3C, and a third layer 153 interposed between the second layer 152 and each of the base 11 and the leads 3A, 3B, and 3C. Crystal grains in the second layer 152 are smaller than crystal grains in the third layer 153. Such a configuration can suppress corrosion.