Abstract: Aspects of the present disclosure are directed to methods and apparatuses for generating laser light. As may be implemented in accordance with one or more embodiments, laser light is generated at a laser light source and is modulated in response to a frequency modulation signal, to generate a plurality of different wavelengths of laser light. The frequency modulation signal is generated, for each particular one of the wavelengths of laser light, at a respective seeding frequency corresponding to the particular one of the wavelengths in which the seeding frequency is different for each of the different wavelengths. Such an approach may, for example, involve generating the frequency modulation signal with a frequency generator circuit and using the frequency modulation signal to control an electro-optical modulator for modulating the wavelength of the laser light.

Abstract: Typically, quantum systems are very sensitive to environmental fluctuations, and diagnosing errors via measurements causes unavoidable perturbations. Here, an in situ frequency-locking technique monitors and corrects frequency variations in single-photon sources based on resonators. By using the classical laser fields used for photon generation as probes to diagnose variations in the resonator frequency, the system applies feedback control to correct photon frequency errors in parallel to the optical quantum computation without disturbing the physical qubit. Our technique can be implemented on a silicon photonic device and with sub 1 pm frequency stabilization in the presence of applied environmental noise, corresponding to a fractional frequency drift of <1% of a photon linewidth. These methods can be used for feedback-controlled quantum state engineering.

Abstract: A wafer may comprise a substrate layer and a plurality of vertical cavity surface emitting lasers (VCSELs) formed on or within the substrate layer. A respective trench-to-trench distance associated with the plurality of VCSELs may vary across the wafer based on a predicted variation of an oxidation rate of an oxidation layer across the wafer.

Abstract: A buried typed semiconductor optical device includes a semiconductor substrate having a pair of grooves extending in a first direction. An upper surface of a buried layer has a first region that is adjacent to a mesa stripe structure, overlaps with a corresponding one of the pair of grooves, is inclined so as to be higher in a second direction from the mesa stripe structure, and on which a passivation film is not formed. The upper surface of the buried layer has a second region that does not overlap with any of the pair of grooves, is flat, and is higher than a lower end of the first region, and on which the passivation film is formed. The upper surface of the buried layer has a connection region between the first region and the second region at a same height as the second region.

Abstract: A semiconductor laser device includes a first cladding including gallium nitride (GaN) on a substrate, a light waveguide on the first cladding, a first contact pattern, a first SCH pattern, a first active pattern, a second SCH pattern, a second cladding and a second contact pattern sequentially stacked on the light waveguide, and first and second electrodes on the first and second contact patterns, respectively.

Abstract: An optical apparatus for depolarizing a laser beam within a fiber MOPA laser is disclosed. The apparatus includes a first phase modulator for spectral broadening, a linear polarizer, an optical coupler, a second phase modulator for depolarizing the laser beam, and a polarization-maintaining optical fiber. The optical coupler divides a linearly-polarized portion of the laser beam equally between fast and slow axes of the second phase modulator. The laser beam delivered by the polarization-maintaining optical fiber is truly unpolarized. The apparatus provides independent control of the spectral broadening and the depolarization to mitigate stimulated Brillouin scattering during subsequent amplification. A method for depolarizing a laser beam, using this apparatus, is also disclosed.

Abstract: A semiconductor laser device includes first heat radiator (10) having first flow path (11) and second flow path (12) inside to allow a flow of a refrigerant and second heat radiator (20) put in contact with an upper surface of the first heat radiator. The first flow path and the second flow path are independent of each other. The second heat radiator includes an insulating member that internally has third flow path (23) communicating with first flow path (11). The semiconductor laser device further includes lower electrode block (60) disposed on a portion of an upper surface of the second heat radiator, submount (30) being made of a conductive material and being disposed on a remainder of the upper surface of second heat radiator (20), semiconductor laser element (40) disposed on an upper surface of submount (30), and upper electrode block (61) disposed such that submount (30) and semiconductor laser element (40) are clamped between the upper electrode block and second heat radiator (20).

Abstract: Embodiments relate to a noise suppressor for suppressing noise of an optical signal, including a core through which the optical signal travels, a clad that is wrapped around the core and configured to expose part of the core, and a graphene layer formed on the part of the core, and a digital optical signal generation system including the same.

Abstract: There is disclosed in one example a fiberoptic communication device, including: a modulator to modulate data onto a laser pulse; and a semiconductor laser source including an active optical waveguide to provide optical gain and support an optical mode, the laser source further including a V-shaped current channel superimposed on the optical waveguide, and disposed to feed the active optical waveguide with electrical current along its length, the current channel having a proximate end to the optical mode, the proximate end having a width substantially matching a diameter of the optical mode, and a removed end from the optical mode, wherein the removed end is substantially wider than the proximate end.

Abstract: A photonic integrated circuit device includes a passive waveguide section formed over a substrate, a quantum cascade laser (QCL) gain section formed over the substrate and adjacent to the passive waveguide section, and a taper section disposed between and in contact with each of the passive waveguide section and the QCL gain section. In some embodiments, the passive waveguide section includes a passive waveguide core layer disposed between a first cladding layer and a second cladding layer. In some examples, the QCL gain section includes a QCL active region disposed between a first confinement layer and a second confinement layer, where the QCL active region has a lower index of refraction than each of the first and second confinement layers. In some embodiments, the taper section is configured to optically couple the QCL gain section to the passive waveguide section.

Abstract: Embodiments described herein provide a layered structure that comprises a substrate that includes a first porous multilayer of a first porosity, an active quantum well capping layer epitaxially grown over the first porous multilayer, and a second porous multilayer of the first porosity over the active quantum well capping layer, where the second porous multilayer aligns with the first porous multilayer.

Abstract: An emitter array may comprise a plurality of emitters and a metallization layer to electrically connect the plurality of emitters. The metallization layer may have a first end and a second end. The plurality of emitters may include a first emitter and a second emitter. The first emitter may be located closer to the first end than the second emitter. The first emitter and the second emitter have differently sized structures to compensate for a first impedance of the metallization layer between the first end and the first emitter and a second impedance between the first end and the second emitter.

Abstract: A light source module includes: laser light sources; parallel light lenses that converts laser beams from the laser light sources to collimated laser beams; a demagnification optical system including that demagnifies the collimated laser beams; an optical fiber; and a condenser lens that converges and couples the laser beams demagnified by the demagnification optical system with the optical fiber; wherein an Abbe number of each of the parallel light lenses is set to a set value suppressing an output fluctuation from the optical fiber to a predetermined value or less, the set value determined based on: a transverse magnification defined by a focal length of a corresponding one of the parallel light lenses, a demagnification of the demagnification optical system, and a focal length of the condenser lens; and a corresponding one of wavelength shifts of the laser beams generated by the laser light source.

Abstract: In various embodiments, pointing errors in a non-wavelength-beam-combining dimension of a laser system are at least partially alleviated via staircased collimation lenses.

Abstract: In embodiments, an apparatus to predict failure of a laser is presented. The apparatus may include a memory to store a reference model of bias current change for a laser as a function of time and temperature, one or more sensors to detect: temperature, elapsed operating time and bias current of the laser, and a processor communicatively coupled to the memory and to the one or more sensors. The processor may be to calculate an actual bias current change ?IA at a current laser temperature, and an expected bias current change ?IE, based at least in part on the reference model and an average operating temperature, subtract ?IE from ?IA, and if the difference is greater than a pre-defined value ?, output a signal. Related methods and non-transitory computer-readable media may also be presented.

Abstract: An on-chip wavelength locker may include an optical waveguide splitter to split an input optical signal received from a laser. The on-chip wavelength locker may include a plurality of integrated periodic optical elements, each to receive a respective portion of the input optical signal after splitting of the input optical signal by the optical waveguide splitter, and provide, based on the respective portion of the input optical signal, a respective periodic output optical signal of a plurality of periodic output optical signals. Each periodic output optical signal, of the plurality of periodic output optical signals, may be phase shifted with respect to other periodic output optical signals of the plurality of periodic output optical signals. The on-chip wavelength locker may include a plurality of integrated photodiodes to receive the plurality of periodic output optical signals in association with wavelength locking the laser.

Abstract: A gas laser apparatus includes: a magnetic bearing including an electromagnet capable of controlling a magnetic force, and configured to rotatably support a rotary shaft of a fan in a magnetically levitated state by the magnetic force, the fan being configured to supply a laser gas; an electromagnet control unit configured to control the magnetic force of the electromagnet based on displacement of a levitated position of the rotary shaft and adjust the levitated position; a motor configured to generate torque for rotating the fan; a magnetic coupling configured to couple the rotary shaft and a drive shaft of a motor with a magnetic attractive force and transmit the torque of the motor to the rotary shaft; an attractive force estimating sensor configured to detect a parameter that enables an attractive force of the magnetic coupling to be estimated; an attractive force measuring unit configured to measure the attractive force of the magnetic coupling based on the detected parameter; and a correction unit confi

Abstract: A beam projector module including a light source configured to output light, a substrate configured to support the light source, an optical device configured to decrease the intensity of the light output to a predetermined space, an optical substrate, in which the optical device is disposed, and configured to transmit the light, and a frame configured to space the optical device apart from the light source by a predetermined distance, and including a support part configured to support the optical substrate, wherein the optical substrate is slidingly inserted through a first slot formed to pass through a first side surface of the frame, and is mounted on the frame such that a portion of an upper surface or a lower surface of the optical substrate contacts the support part.

Abstract: Systems and methods according to present principles provide, at room temperature, a bound state in the continuum laser that harnesses optical modes residing in the radiation continuum but nonetheless may possess arbitrarily high quality factors. These counterintuitive cavities are based on resonantly trapped symmetry-compatible modes that destructively interfere. Such systems and methods may be applied towards coherent sources with intriguing topological properties for optical trapping, biological imaging, and quantum communication.

Abstract: A laser oscillator unit includes an amplification unit configured to amplify laser light and emit amplified laser light from an emitting portion; a case covering the amplification unit; and an outer support mechanism and an inner support mechanism provided on the case. The case is formed with a window portion. An outer movable leg allows the case to slide in a radial direction around an outer fixed leg. An inner movable leg allows the amplification unit to slide in the radial direction around an inner fixed leg. A straight line passing through a center of the outer fixed leg and a center of the inner fixed leg intersects with a straight line passing through the emitting portion and the window, and a laser optical axis emitted from the emitting portion and a laser optical axis emitted from the window portion coincide with each other.