Abstract: In one exemplary embodiment, apparatus is provided with a plurality of laser diodes, sensing means and control means. During normal operation, the laser diodes produce a mixed light. The sensing means measures light that is output by the laser diodes; and the control means 1) compares the measured light to a spectral reference, and 2) sets drive signals of the laser diodes in response to the comparison. In a related and exemplary method, 1) a mixed light is produced using a plurality of laser diodes of different colors, 2) a measurement of light produced by the laser diodes is compared to a spectral reference, and 3) drive signals of the laser diodes are automatically set in response to the comparison.

Abstract: In one aspect, a vertical cavity surface emitting laser (VCSEL) is operable to generate single-mode laser light at an operative wavelength. The VCSEL includes a light-emitting surface and a monolithic longitudinal stack structure. The longitudinal stack structure includes a first mirror, a second mirror, and a cavity region. The cavity region is disposed between the first mirror and the second mirror and includes an active light generation region and a cavity extension region. The longitudinal stack structure further includes an ion-implanted current confinement region. A VCSEL array incorporating the above described VCSEL and a method of making the above-described VCSEL also are described.

Abstract: Coupled opto-electronic oscillators with a whispering-gallery-mode (WGM) optical resonator inside the laser cavity to produce oscillation signals out of the optical spectral range, e.g., RF or microwave frequencies.

Abstract: A laser beam containment system includes a number of optics that direct a laser beam produced by a laser beam source along a path to a point of application of the laser beam. One or more hollow tubes are positioned in an arrangement such that the laser beam passes through the hollow tubes. The hollow tubes are also adjustably positioned relative to the laser beam objects to allow for access to the optics for maintenance and adjustment of the optics. Locking mechanisms provide control of the adjustment features of the containment tubes.

Abstract: A semiconductor laser device comprises an active layer, a cladding layer, an end face for emitting light. A low-reflective film is provided on the end face. The reflectance of the low-reflective film changes with wavelength. A wavelength at which the reference of the low-reflective film is minimized is on the long wavelength side of a wavelength at which the gain of the semiconductor laser device is maximized. The gain and the loss of the semiconductor laser device become equal at a wavelength only in a wavelength region in which the reflectance of the low-reflective film decreases with increasing wavelength. The reflectance of the low-reflective film is preferably set to 1% or less at the wavelength at which the gain of the semiconductor laser device is maximized.

Abstract: A solder-free laser module which comprises at least one laser chip clamp-mounting between electrodes. The laser module includes: some electrodes facing each other and having opposite poles; insulating separators placed between the facing surfaces of the electrodes to prevent direct contact between them and their short-circuiting; laser chips mounted between the facing surfaces of said electrodes, making contact with the electrodes, and clamping means for bringing the electrodes facing each other more closely together to ensure their contact with the laser chips positioned between them, thereby ensuring electrical power supply to the aforesaid laser chips and dissipation of the heat generated. The invention further relates to a method for assembling the aforesaid laser module.

Abstract: A semiconductor laser device has an active layer, a first cladding layer formed on the active layer, and a second cladding layer formed on the first cladding layer. The first cladding layer is doped with magnesium as a first impurity to have a high resistivity. The second cladding layer is doped with zinc as a second impurity to have a resistivity lower than the resistivity of the first cladding layer.

Abstract: A surface emitting semiconductor laser device including a substrate, a bottom DBR, and a mesa post having a layer structure, the layer structure including a top DBR including a plurality of pairs, each of said pairs including an Al-containing high-reflectivity layer and an Al-containing low-reflectivity layer, an active layer structure sandwiched between the DBRs for emitting laser, and a current confinement layer disposed within or in a vicinity of one of the DBRs, the current confinement layer including a central current injection area and an annular current blocking area encircling the central current injection area, the annular current blocking area being formed by selective oxidation of Al in an AlXGa1-XAs layer (0.95?x<1) having a thickness below 60 nm, the Al-containing low-reflectivity layer including Al at an atomic ratio not more than 0.8 and below 0.9.

Abstract: A conductive element with a lateral oxidation barrier is provided for the control of lateral oxidation processes in semiconductor devices such as lasers, vertical cavity surface emitting lasers and light emitting diodes. The oxidation barrier is formed through modification of one or more layers which initially were receptive to oxidation. The quality of material directly below the oxidation barrier may be preserved. Related applications include the formation of vertical cavity surface emitting lasers on non-GaAs substrates and on GaAs substrates.

Abstract: Provided is a tunable external cavity laser diode using a variable optical deflector wherein the variable optical deflector, in which a refractive index varies according to an electrical signal, is arranged in a triangular shape between a concave diffraction grating and a reflective mirror. Since a resonant frequency is changed using the electrical signal rather than the mechanical movement, the stable operation and continuous high-speed tenability may be enabled. In addition, when the tunable external cavity laser diode according to the present invention is implemented in an InP/InGaAsP/InP slab waveguide, a variable time determined by the carrier lifetime may be reduced to several nanoseconds or less, the miniaturization is enabled, and the manufacturing costs are significantly reduced due to the process simplification.

Abstract: A semiconductor laser device produces a laser beam, which is adapted to be expanded into a linear laser beam for use as stimulating rays for an image read-out operation for reading out a radiation image having been stored on a stimulable phosphor sheet. The semiconductor laser device comprises a semiconductor laser chip for producing the laser beam, a package for accommodating the semiconductor laser chip therein, and a radiating window, which is fitted to the package and allows the laser beam having been produced by the semiconductor laser chip to pass therethrough. A surface of the radiating window is coated with an anti-reflection film having a reflectivity of at most 1.0% with respect to a wavelength of the laser beam having been produced by the semiconductor laser chip.

Abstract: A semiconductor laser device includes: a first cladding layer, which is made of a nitride semiconductor of a first conductivity type and is formed over a substrate; an active layer, which is made of another nitride semiconductor and is formed over the first cladding layer; and a second cladding layer, which is made of still another nitride semiconductor of a second conductivity type and is formed over the active layer. A spontaneous-emission-absorbing layer, which is made of yet another nitride semiconductor of the first conductivity type and has such an energy gap as absorbing spontaneous emission that has been radiated from the active layer, is formed between the substrate and the first cladding layer.

Abstract: An optical resonator includes a first substrate and a second substrate which face each other, the first substrate having a flat main surface on which a first reflective mirror is provided and the second substrate having a concave portion on which a second reflective mirror is provided and a flat portion which surrounds the concave portion. The main surface of the first substrate and the flat portion of the second substrate are bondable. In addition, a laser oscillator includes a solid-state laser medium and a substrate, the solid-state laser medium having a main surface on which a first reflective mirror is provided and the substrate having a concave portion on which a second mirror is provided and a flat portion which surrounds the concave portion. The first and the second reflective mirrors serve as a laser resonator.

Abstract: A wavelength locker. The wavelength locker can be mounted within an optical transceiver on a submount with the laser diode. The wavelength locker utilizes light emitted by the back facet of the laser to monitor the wavelength and power of the laser. The light is separated into two portions, at least one of which is passed through a filter to shift the wavelength thereof. Separate monitor diodes or photosensitive areas of a single monitor diode are used to measure the output of each portion of light. The outputs are analyzed to determine the wavelength of the light emitted from the back facet as well as the power of the laser and a controller can then change the temperature of the laser or otherwise adjust the wavelength of the laser when the wavelength locker detects that the wavelength of the laser is changing.

Abstract: An optically pumped radiation-emitting semiconductor device with a surface-emitting quantum well structure (10), which has at least one quantum layer (11), and an active layer (8) for generating pump radiation (9) for optically pumping the quantum well structure (10), which is arranged parallel to the quantum layer (11). The semiconductor device has at least one emission region (12), in which the quantum well structure (10) is optically pumped, and at least one pump region (13). The quantum well structure (10) and the active pump layer (8) extend over the pump region (13) and over the emission region (12) of the semiconductor device, and the pump radiation (9) is coupled into the emission region (12) in the lateral direction.

Abstract: A multi-channel light source includes a semiconductor optical amplifier for generating light of a wide wavelength band and outputting the generated light through a first end and a second end. The source further includes a Fabry-Perot (FP) resonator for resonating the light inputted from the semiconductor optical amplifier to generate an FP fringe and outputting the FP fringe to the semiconductor optical amplifier. The semiconductor optical amplifier amplifies the FP fringe inputted from the FP resonator and outputs the amplified FP fringe through the first end.

Abstract: A current output of a drive signal, modulated between two current settings, is applied to a laser diode, e.g. VCSEL. The settings are selected such that laser diode's power output meets the average power and peak power limits of the eye safety standards. The drive signal having a duty cycle toggling between the two settings. The duty cycle is selected such that the average and peak power limits are met for the given upper current setting. The drive circuit may include an analog modulator or digital analog converter (DAC) for maintaining the lower and upper current settings. When the drive circuit is implemented as an integrated circuit, the DAC may be incorporated into the IC. The sensitivity of the DAC is selected to maintain the desired lower and upper current settings.

Abstract: A nitride-based semiconductor light-emitting device capable of stabilizing transverse light confinement is obtained. This nitride-based semiconductor light-emitting device comprises an emission layer, a cladding layer, formed on the emission layer, including a first nitride-based semiconductor layer and having a current path portion and a current blocking layer, formed to cover the side surfaces of the current path portion, including a second nitride-based semiconductor layer, while the current blocking layer is formed in the vicinity of the current path portion and a region having no current blocking layer is included in a region not in the vicinity of the current path portion. Thus, the width of the current blocking layer is reduced, whereby strain applied to the current blocking layer is relaxed. Consequently, the thickness of the current blocking layer can be increased, thereby stabilizing transverse light confinement.

Abstract: A semiconductor laser device includes a layer structure of a first conductive cladding layer, an active layer, and a second conductive cladding layer sequentially grown on a first conductive semiconductor substrate; and a light emitting facet from which a laser beam having a first wavelength is emitted. Refractive indexes of the first and the second conductive cladding layers with respect to the first wavelength are lower than an effective refractive index with respect to the first wavelength. With respect to a light having a second wavelength incident on the light emitting facet from outside, the refractive index of at least one of the first and the second conductive cladding layers is equal to or higher than the effective refractive index with respect to the second wavelength.

Abstract: An accelerator circuit is incorporated in a laser diode system for accelerating the turn-on operation of the laser diode independent of the control loop bandwidth of the laser diode system. The accelerator circuit provides a boost current to a compensation capacitor upon laser turn-on which compensation capacitor operates to establish the control loop bandwidth of the laser diode system. The boost current enables the control loop to increase the bias current to the laser diode quickly. When the laser diode reaches the desired operating point, the boost current is terminated and the control loop of the laser diode system resumes normal control of the bias current. In one embodiment, the accelerator circuit includes a timer circuit controlling a current source to implement open loop turn-on control. In another embodiment, the accelerator circuit includes a comparator circuit working in conjunction with an one-shot logic circuit for providing close loop control.