Abstract: Systems and methods are provided for imaging using complex lasers. In general, a complex laser may be used as an electromagnetic source for an imaging application. The use of a lower spatial coherence configured complex laser in imaging applications may advantageously mitigate coherent artifacts in imaging such as cross-talk and speckle and improve overall image quality. Imaging applications where a complex laser may be useful include both incoherent imaging applications, such as digital light projectors and traditional microscopy, and coherent imaging applications, such as optical coherence tomography (OCT) and holography. The systems and methods provided also enable controlling the degree of spatial coherence of a complex laser.

Abstract: A leakage light removal structure 70 is used to remove leakage light in an optical fiber 140 having a core 160, a cladding 162 having a refractive index lower than the core 160, and a covering material 164 having a refractive index higher than the cladding 162. The leakage light removal structure 70 has a fiber housing 72 that houses part of the optical fiber 140, a covering material extension portion 175 covering part of a whole circumference of the cladding 162 by extending part of the covering material 164 along a longitudinal direction of the optical fiber 140 within the fiber housing 72, and a cladding exposure portion 174 in which a portion of the whole circumference of the cladding 162 other than the covering material extension portion 175 is exposed within the fiber housing 72. The covering material 164 may be covered with a resin 76 having a refractive index not more than the refractive index of the covering material 164.

Abstract: A low voltage laser device having an active region configured for one or more selected wavelengths of light emissions.

Abstract: The invention relates to an external cavity tunable laser with dual beam outputs. The first laser cavity of the tunable laser comprises a first laser cavity mirror, a laser gain medium, an intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter, a tunable Fabry-Perot tunable filter, a second reflection mirror all disposed inside a laser cavity sequentially, and a laser driver and control system. The laser cavity beam reflected by the first laser cavity mirror enters the tunable acousto-optic filter to generate a zeroth order diffracted beam as the first laser output beam. The laser cavity beam reflected by the second laser cavity mirror enters the tunable acousto-optic filter to generate a zeroth order diffracted beam as the second laser output beam. The tunable laser further comprises a wavelength locker outside the laser cavity.

Abstract: A surface emitting laser having a wide wavelength tunable band is provided. A surface emitting laser includes a first reflecting mirror (102); a second reflecting mirror (116); and an active layer (104) arranged between the first reflecting mirror (102) and the second reflecting mirror (116), a gap being formed between the second reflecting mirror (116) and the active layer (104), an oscillation wavelength being tunable. The second reflecting mirror (116) includes a beam (108) comprising a single-crystal semiconductor, and a dielectric multilayer film (110) supported by the beam (108), and the dielectric multilayer film (110) is arranged in an opening (118) formed in the beam (108).

Abstract: A vertical-cavity surface-emitting laser (VSCEL) and method for producing a VCSEL are described, the VCSEL including an undercut active region. The active region of the VCSEL is undercut relative to current-spreading layers of the VCSEL, such that a width of a tunnel junction of the VCSEL overgrown by a current spreading layer is less than a width of an active region of the VCSEL, and a width of the active region of the VCSEL is less than a width of the overgrown current-spreading layer, such that the VCSEL including the undercut active region is configured to transmit data at speeds greater than 25 gigabits/second.

Abstract: In a semiconductor light emitting element provided with an active layer 4, a pair of cladding layers 2, 7 between which the active layer 4 is interposed, and a phase modulation layer 6 optically coupled to the active layer 4, the phase modulation layer 6 includes a base layer 6A and a plurality of different refractive index regions 6B having different refractive indices from the base layer 6A. When an XYZ orthogonal coordinate system having a thickness direction of the phase modulation layer 6 as a Z-axis direction is set and a square lattice of a virtual lattice constant a is set in an XY plane, each of the different refractive index regions 6B is disposed so that a centroid position G thereof is shifted from a lattice point position in a virtual square lattice by a distance r, and the distance r is 0<r?0.3a.

Abstract: A method of forming a pair of edge-emitting lasers is provided. The method includes forming a mesa from a substrate, forming a cover layer on the substrate around the mesa, and forming a first barrier layer on each of opposite sidewalls of the mesa. The method further includes forming a quantum well layer on each of the barrier layers, forming a second barrier layer on each of the quantum well layers, and forming a cladding layer on each of the second barrier layers.

Abstract: The present invention relates to an artificial light system for modulating circadian rhythms, increasing vigilance and influencing light-associated psychological conditions such as seasonal affective disorder. The system of the invention comprises a source of a green and/or red light and a source of blue light both light sources being controlled by a computer to provide predetermined light conditions. More specifically, the computer is programmed to provide pulses of blue light and continuous or pulsed red light, to enhance the efficacy of blue light, reduce blue-light hazard and avoid stroboscopic effect.

Abstract: An optical semiconductor device includes: an n-type semiconductor substrate; an n-type cladding layer provided on the n-type semiconductor substrate; an active layer of a semiconductor laser provided on the n-type cladding layer; a waveguide layer of a waveguide provided on the n-type cladding layer and having a side facing a side of the active layer; a p-type cladding layer provided on the active layer and the waveguide layer; and a middle layer provided between the side of the active layer and the side of the waveguide layer, provided between the n-type cladding layer and the waveguide layer, not provided on the active layer, and having a band gap greater than a band gap of the waveguide layer.

Abstract: A single mode fiber pulsed oscillator includes an all normal dispersion ring cavity provided with a mode-locking fiber loop component and a giant chirp generating fiber component. The mode-locking fiber loop component is configured with a hybrid of NOLM and NALM configurations which is operative to induce a first phase acquisition of a spectrally narrow pulse due to SPM. The giant chirp generating fiber loop component is configured to induce the additional phase acquisition to the pulse broadened in the mode-locking fiber component so as to generate a pulse with a giant chirp. The fiber loop components each include a fiber amplifier and a coil of fiber. The amplifiers each are configured with an active fiber provided with a core which supports multiple transverse mode in a range of wavelength except for the desired wavelength at which the core is configured to support a single fundamental mode.

Abstract: A power supply apparatus includes a power supply for supplying power to a laser oscillator. A reactor has one end serially connected to the laser oscillator and another end serially connected to the power supply, and a parallel diode configures a closed circuit for serial connection of the laser oscillator and the reactor. A current detector detects a current flowing in the reactor, and a first switching device is connected in parallel to the laser oscillator and drives the laser oscillator with pulses. An energy consumption circuit prefetches a current command value based on a control signal from a controller upon driving the laser oscillator with pulses, and when the current command value is smaller than a current command value of a previous pulse, the energy consumption circuit consumes energy until the current command value reaches a predetermined target current value.

Abstract: A system for dynamically adjusting a bias voltage for a laser diode or a light emitting diode is provided. An output voltage of the laser diode is measured and a level of a supply voltage applied to the laser diode is adjusted to change the bias voltage to the laser diode to manage power usage and avoid saturation of the laser diode. Also, a junction temperature of a laser diode may be estimated by mapping a measured output voltage and known current to device characteristic data based on temperature and the supply voltage adjusted in order to bias the laser diode to compensate for a temperature change. Further, data indicating an intensity level of data to be rendered by the laser diode is used to adjust the second supply voltage to bias the laser diode in advance of rendering the data.

Abstract: A configuration of a DFB laser-based wavelength tunable laser is well known, but long resonators have difficulty in forming uniform resonators due to production variations, thereby inducing limitation in narrowing the spectral linewidth in the DFB laser-based wavelength tunable laser as well. In the semiconductor laser device of the present invention, a semiconductor laser that oscillates in a single mode and a low-loss lightwave circuit using SiO2 glass are arranged on the common substrate. The lightwave circuit is configured such that part of output light from the semiconductor laser propagates through a certain length of an optical path, and then is reflected by a reflector and is fed back to the semiconductor laser. Output light from the semiconductor laser and an input waveguide of the lightwave circuit can also be configured to be optically connected directly to each other. The present invention can provide a compact laser device with a narrowed spectral linewidth and stable wavelength controllability.

Abstract: The present disclosure provides an optical sub-system for a passive, mode-locked laser optical system. The optical sub-system may include a graphene-based saturable absorber and an optical device configured to control dispersion properties of the laser optical system. The graphene-based saturable absorber may be supported by the optical device.

Abstract: A semiconductor light-emitting element includes a laminated structure which has an active layer between a first conductivity-type semiconductor layer and a second conductivity-type semiconductor layer, a first semiconductor layer which includes at least the first conductivity-type semiconductor layer of the laminated structure, an insulation film which is formed on the first semiconductor layer and has an opening, and a second semiconductor layer which is formed on the insulation film and includes at least the second conductivity-type semiconductor layer of the laminated structure. The second semiconductor layer includes a first region facing the opening of the insulation film and a second region not facing the opening, and the second region has a portion with a higher impurity concentration than the first region.

Abstract: Provided herein are systems and methods for switching the generation of light emissions using charge separation in a gain medium to manipulate carrier lifetimes. For a given output pulse energy, extended carrier lifetimes may allow carrier generation powers to be reduced and/or carrier generation times to be extended. L-switching of light output from a gain medium may be combined with other switching schemes utilizing different approaches to control lasing, such as Q-switching.

Abstract: Disclosed is a device for generating a laser radiation including a box and an electrode, the electrode including a column extending along an axial direction and a collar surrounding the column and having a first face perpendicular to the axial direction and a second face parallel to the first face, the second face facing the box. The generating device includes a ring having a third face bearing against the box, the ring defining a hole emerging on the third face and accommodating the collar, the hole being defined along the axial direction by a bearing face arranged in the ring, perpendicular to the axial direction and facing the box, the first face bearing against the bearing face.

Abstract: According to an example of the present disclosure a semiconductor laser diode includes a layer of graphene between an active laser region and a semiconductor substrate structure. The semiconductor laser diode may further include a first pair of electrodes to apply a potential difference across the active laser region and a second pair of electrodes to apply a potential difference across the layer of graphene.

Abstract: This solid laser amplification device has: a laser medium part that has a solid medium, into which a laser light enters from an entrance part and from which the laser light (L) is emitted to the outside from an exit part, and an amplification layer, which is provided on the surface of the medium, receives the laser light in the medium, and amplifies and reflects said light toward the exit part; a microchannel cooling part that cools the amplification layer; and a thermally conductive part that is provided so as to make contact between the amplification layer and the cooling part and transfers the heat of the amplification layer to the cooling part.