Abstract: A III-nitride semiconductor laser device including: a laser structure including a support base and a semiconductor region, the support base including a hexagonal III-nitride semiconductor and having a semipolar primary surface, and the semiconductor region being provided on the semipolar primary surface of the support base; and an electrode provided on the semiconductor region of the laser structure, the semiconductor region including a first cladding layer, a second cladding layer, and an active layer.

Abstract: An optically pumped laser oscillator or amplifier includes a laser head having a gain medium exhibiting polarization-dependent absorption along two crystallographic axes and a pump source producing a pump beam. The medium's absorption coefficients along both said crystallographic axes are equal or the difference between the absorption coefficients relative to the lowest absorption coefficients R=Abs(?c??a)/(min(?c, ?a)) is reduced at least by a factor of two compared to the same relative difference between the two absorption coefficients at the medium's absorption peaks, used for conventional pumping by pumping with unpolarized or partially polarized pump light at a wavelength around which the average absorption coefficients along both of said crystallographic axes are equal or present a relative difference that is reduced by a factor of two or better compared to conventional pumping around the medium's absorption peaks.

Abstract: Unidirectionality of lasers is enhanced by forming one or more etched gaps (78, 80) in the laser cavity. The gaps may be provided in any segment of a laser, such as any leg of a ring laser, or in one leg (62) of a V-shaped laser (60). A Brewster angle facet at the distal end of a photonic device coupled to the laser reduces back-reflection into the laser cavity. A distributed Bragg reflector is used at the output of a laser to enhance the side-mode suppression ratio of the laser.

Abstract: A semiconductor laser device has structure including: a semiconductor laser chip having an emission surface and a reflection surface which are opposing end surfaces of a resonator; and a photodiode for detecting light that exits from the reflection surface side, the photodiode being used in a wavelength band where a sensitivity of the photodiode rises as a wavelength lengthens, in which the emission surface has a first dielectric multilayer film formed thereon and the reflection surface has a second dielectric multilayer film formed thereon, and in which, when a wavelength at which a reflectance of the first dielectric multilayer film peaks is given as ?f and a wavelength at which a reflectance of the second dielectric multilayer film peaks is given as ?r, a relation ?f<?r is satisfied.

Abstract: The use of reflecting surfaces that are inclined towards one another enables the multiple reflection of a beam path to be achieved in a laser structure. This permits the realization of compact laser assemblies. The introduction of beam-influencing media between the reflective surfaces or the configuration of said reflective surfaces from or using media of this type allows the use of the multiple reflection for influencing parameters of the radiation or radiation field.

Abstract: A the vertical-cavity surface-emitting laser includes a stripe-shaped active medium (10) having an emission maximum at a first wavelength (?1), wherein a first reflector (18) is arranged below the stripe-shaped active medium (10) and a second reflector (20) is arranged above the stripe-shaped active medium (10), with the first reflector (18) facing the second reflector (20), wherein the first reflector (18) and a second reflector (20) have a reflectivity maximum in the region of the first wavelength (?1), wherein a third reflector (12) and a fourth reflector (13) are each arranged on a side above or next to the stripe-shaped active medium (10), wherein the third reflector (12) faces the fourth reflector (13), and wherein the third reflector (12) and the fourth reflector (13) have a reflectivity maximum in the region of a second wavelength (?2), wherein the first wavelength (?1) is greater than the second wavelength (?2).

Abstract: A laser device, which includes an oscillator unit having a rectangular-solid-shaped housing containing a laser oscillator for generating and outputting a laser light; an amplifier unit having a rectangular-solid-shaped housing containing an amplifier that receives and amplifies the laser light to output; and, a group of optical elements including optical elements provided on a laser light path, wherein the laser device includes one or more amplifier units, and the oscillator and the amplifier units are arranged such that surfaces having a wide area other than a surface having a smallest area of a housing of the oscillator unit and a housing of at least one amplifier unit are next to and face each other, or such that surfaces having a wide area other than a surface having a smallest area of a housing of at least two amplifier units are next to and face each other.

Abstract: A semiconductor laser outputs a laser light from an output facet of a waveguide having an index waveguide structure, via a lens system. The waveguide includes, in order from a rear facet opposite to the output facet, a first narrow portion, a wide portion that is wider than the first narrow portion, a second narrow portion narrower than the wide portion, a first tapered portion formed between the first narrow portion and the wide portion, which expands toward the wide portion, and a second tapered portion formed between the wide portion and the second narrow portion, which narrows toward the second narrow portion. Each of the first narrow portion, the wide portion, and the second narrow potion has a uniform width.

Abstract: A Laser device with phase front regulation, including a resonator with a beam path, a laser medium located within the resonator, and a phase front regulating unit located within the resonator; a coupling element; an uncoupling element; and phase front controller and a phase front sensor. A measuring laser beam can impact first the coupling element, then the laser medium, then the phase front regulating unit, then the uncoupling element, and then the phase front sensor. The disturbance of the phase front of the laser medium is transferable to the measuring laser beam. The disturbance of the measuring laser beam and the working laser beam can be corrected by the phase front regulating unit. Sensor data can be received from the phase front sensor and can be processed by the phase front controller. Regulating unit signals for the phase front regulating unit can be generated by the phase front controller.

Abstract: A laser cooling system includes a substrate, an REO layer of single crystal rare earth oxide including at least one rare earth element positioned on the surface of the substrate, and an active layer of single crystal semiconductor material positioned on the REO layer to form a semiconductor-on-insulator (SOI) device. Light guiding structure is at least partially formed by the REO layer so as to introduce energy elements into the REO layer and produce cooling by anti-Stokes fluorescence. The active layer of single crystal semiconductor material is positioned on the REO layer in proximity to the light guiding structure so as to receive the cooling.

Abstract: Monolithic opto-isolators and arrays of monolithic opto-isolators are disclosed. The monolithic opto-isolators are manufactured in a single semiconductor wafer where they may be tested at the wafer level before each opto-isolator is singulated from the wafer. The monolithic opto-isolators include a VCSEL monolithically produced adjacent to a photodiode where an axis of optical signal transmission of the VCSEL is substantially parallel to an axis of optical signal reception by the photodiode.

Abstract: A laser includes an optically pumped semiconductor OPS gain-structure. The apparatus has a laser-resonator which includes a mode-locking device for causing the laser to deliver mode-locked pulses. The resonator has a total length selected such that the mode-locked pulses are delivered at a pulse repetition frequency of about 100 MHz. An optical arrangement within the resonator provides that radiation circulating in the resonator makes a plurality of incidences on the OPS gain-structure with a time less than the excited-state lifetime of the gain-structure between successive incidences.

Abstract: Laser modules using two-dimensional laser diode arrays are combined to provide an intense laser beam. The laser diodes in a two-dimensional array are formed into rows and columns, and an optical assembly images light generated by laser diodes in a column into an optical fiber. The laser light outputs of the laser modules are combined by a spectral combiner into an optical fiber to form an intense laser beam.

Abstract: A laser device having a wave emission within a frequency range of 0.5 to 5 THz, includes a semiconductor heterostructure having a cylindrical form with a circular cross-section and including: a first optically nonlinear semiconductor material layer including an emitting medium configured to emit at least two optical whispering gallery modes belonging to the near-infrared spectrum, the two whispering gallery modes being confined within the first layer and enabling the generation, within the first layer, of radiation within an electromagnetic whispering gallery mode having a frequency of 0.

Abstract: An optical assembly (OSA) that installs a semiconductor optical device mounted on a thermo-electric controller (TEC) is disclosed. The TEC in the upper plate thereof is mechanically connected to the housing, or to the block stiffly fixed to the housing by a bridge made of stiff material. The bridge preferably extends along the optical axis to show enhanced durability against the impact caused by an external ferrule abutting against the receptacle of the OSA.

Abstract: According to the repetition frequency control device, a master laser outputs a master laser light pulse the repetition frequency of which is controlled to a predetermined value. A slave laser outputs a slave laser light pulse. A reference comparator compares a voltage of a reference electric signal the repetition frequency of which is the predetermined value and a predetermined voltage with each other, thereby outputting a result thereof. A measurement comparator compares a voltage based on a light intensity of the slave laser light pulse and the predetermined voltage with each other, thereby outputting a result thereof. A phase difference detector detects a phase difference between the output from the reference comparator and the output from the measurement comparator. A loop filter removes a high-frequency component of an output from the phase difference detector.

Abstract: A light source apparatus includes an optical resonator formed by an optical amplification medium and an optical switch. The optical switch includes a saturable absorber and changes its transmittance or reflectance when receiving an optical pulse emitted from a light irradiation source which includes a wavelength-tunable light source. The light source apparatus emits amplified light from the optical resonator in correspondence with the center wavelength of the optical pulse from the wavelength-tunable light source. The relationship between a length L and an effective refractive index n of the optical resonator and a repetition frequency f of the optical pulse satisfies a condition L<c/(nf), and a relationship between the length L and a recovery time ? in which the changed transmittance or reflectance of the optical switch recovers satisfies a condition ?>(nL)/c.

Abstract: A method for quasi-synchronous tuning of laser wavelength or frequency of grating external-cavity laser and a corresponding laser are provided. A grating or mirror is rotated around a quasi-synchronous tuning point (Pq) to achieve the quasi-synchronous tuning of frequency selections by grating and resonance cavity, wherein, on the xOy coordinate plane, from the perspective of actual physical space of the laser, the rotation center Pq(xq, yq) satisfying the quasi-synchronous tuning condition can be considered as being extended from the rotation center P0(x0, y0) under the conventional synchronous tuning condition to the region enclosed by two parabolas near P0. According to the present disclosure, approximately-synchronous tuning of laser is achieved with simple and flexible designs.

Abstract: Illuminator module comprising VCSEL arrays with planar electrical contacts, readily adaptable for surface mounting, is provided. Monolithic VCSEL arrays are configured in array patterns on two and three-dimensional surfaces. Illuminator modules are easily expandable by increasing the array size or by modularly arranging more arrays with or without a transparent substrate. Different shapes of illuminator modules may be configured by tiling array modules monolithically on a common substrate, or by tiling small modules. The surface mountable illuminator modules are easily assembled on a thermally conductive surface that may be air or liquid cooled for efficient heat dissipation. Array modules may be integrated with other electronic circuits such as current drivers, sensors, controllers, processors, etc.

Abstract: In this semiconductor laser apparatus, a first wire-bonding portion is arranged at a position in a fourth direction from a first semiconductor laser device and in a first direction from a photodetector, and a second wire-bonding portion is arranged at a position in the fourth direction from the first semiconductor laser device and in a third direction from the first wire-bonding portion. A third wire-bonding portion is arranged at a position in a second direction from a third semiconductor laser device and in the first direction from the photodetector, and a fourth wire-bonding portion is arranged at a position in the second direction from the third semiconductor laser device and in the third direction from the third wire-bonding portion.