Abstract: A surface emitting semiconductor laser is formed from a substrate having a first mirror formed thereon. The first mirror includes semiconductor layers of a first conductivity type. A second mirror is formed over the substrate and includes semiconductor layers of a second conductivity type. An active region is disposed between the first and second mirrors, with a current confining layer being disposed between the first and second mirrors. A compound semiconductor layer is formed over the second mirror and an electrode is formed on the compound semiconductor layer. A protective film covers the compound semiconductor layer and partially covers the electrode. The electrode is formed by a lift-off process and uses an opening-pattern that is formed by plasma ashing.

Abstract: A combined-laser-light source includes: a plurality of semiconductor lasers; an optical fiber; and an optical system which converges a bundle of laser beams emitted from the plurality of semiconductor lasers, and makes the converged bundle of the laser beams enter the core of the optical fiber so that the laser beams are combined in the optical fiber when the laser beams pass through the optical fiber. The optical system is aligned with the optical fiber so that the converged bundle of the laser beams is incident on an area of an end face of the core when steady temperature control is performed on the combined-laser-light source, where the area is concentric with the end face of the core, and has a diameter equal to or smaller than half of the diameter of the core.

Abstract: An improved tunnel junction structure and a VCSEL that uses this structure is disclosed. The tunnel junction includes first, second, and third layers that include materials of the InP family of materials. The first layer is doped with n-type dopant species to a concentration of 1019 dopant atoms per cm3 or greater. The second layer is doped with Zn to a similar concentration and is in contact with the first layer. The interface between the first and second layers forms a tunnel junction. The third layer includes a material that retards the diffusion of Zn out of the second layer. The third layer preferably includes undoped AlInAs. The tunnel junction structure of the present invention can be utilized in a VCSEL having an active layer between first and second mirrors that are both constructed from n-type semiconductor layers.

Abstract: A method and apparatus for driving a laser diode source, such as a laser diode or a laser diode array. The driver controlling current in response to a signal indicative of excessive current or current density. The signal may be derived from the drive current, the voltage across the laser diode source or the impedance of the laser diode source. The circuit may be pulsed using a switch, such as a GCT. The current to generate drive the laser diode source provided by a capacitive or inductive charging circuit.

Abstract: Provided is a semiconductor laser diode. The semiconductor laser diode includes a first material layer, an active layer, and a second material layer, characterized in that the semiconductor laser diode includes: a ridge waveguide, which is formed in a ridge shape over the second material layer to define a channel defined so that a top material layer of the second material layer is limitedly exposed, and in which a second electrode layer which is in contact with the top material layer of the second material layer via the channel is formed; and a first protrusion, which is positioned at one side of the ridge waveguide and has not less height than that of the ridge waveguide.

Abstract: A method for stabilizing a laser frequency using sub-Doppler spectral spectrum of atoms, and a laser frequency stabilization device used in the method which is comprised of a gas charged cell, a laser, a laser frequency adjusting means, a laser beam dividing means for dividing the laser beam into a pump beam and a probe beam, a photo detector for measuring intensity of the probe beam after passed through the cell, an ON/OFF means for cutting off the pumping beam at a constant time interval, a computing means for obtaining the intensity of the probe beam, a demodulated signal of the probe beam, the difference in intensity between the probe and pumping beam, and a difference in demodulated signal, and a feedback means which feeds back the information to the laser frequency adjusting means, thereby stabilizing the frequency of the laser.

Abstract: A high power driver system has a predetermined number of driver modules for driving a high power device such as a laser-emitting device. Each driver module has a driver circuit and a corresponding feedback circuit. The driver circuits respectively generate driving currents, and then the driving currents are collected to drive the high power laser-emitting device or other high power devices. In addition, these feedback circuits of the driver modules receive the same detection signal that represents the output power of the high power laser-emitting device. Then, each feedback circuit responds to the same detection signal to generate a feedback signal, respectively, which makes the corresponding driver circuit carry out a feedback action for adjusting the driving currents.

Abstract: Disclosed is a diode-pumped solid-state laser having an asymmetrical optical resonator provided with at least two resonator mirrors, inside said resonator being provided at least one thermal lens having an optical refractive power D and having two principal planes respectively and said resonator being definable by the following stability criteria: 0<G1·G2<1 with G1=1?L*/R1?D·d2 G2=1?L*/R2·D·d1 and L*=d1+d2?D·d1·d2 d1,d2 the distances of the resonator mirror from the principal planes of the thermal lens R1, R2 the radii of curvature of the resonator mirrors.

Abstract: A laser diode module with a built-in high-frequency modulation IC used to remove the reflected noise generated as the laser beam reads the signal to be played back and directly packaged within a metal cap. The high-frequency modulation IC creates an electrical connection through wire bonding with several connection legs and the laser diode module. The packaged laser diode module has four connection legs. Two of these connection legs act as a positive and a negative terminal for supplying power to the built-in high-frequency modulation IC. The other two connection legs are electrically connected to an external automatic power control (APC) circuit and act as the positive terminal of the laser diode and the photo diode, respectively. In this way, the inconvenience of externally attaching a high-frequency current producing circuit board can be avoided, the productivity can be enhanced and the radiation of electromagnetic interference (EMI) can be reduced.

Abstract: A semiconductor laser device having a waveguide constructed in a stack of layers including, on a substrate transparent and having a refractive index ns for laser light, a first clad layer of a refractive index nc1, a second clad layer of a refractive index nc2, a third clad layer of a refractive index nc3, a first conductivity type guide layer of a refractive index ng, an active quantum well layer, a second conductivity type guide layer, a second conductivity type clad layer, and a second conductivity type contact layer deposited in this order, wherein the waveguide has an effective refractive index ne, and a relationship of nc2<(nc1, nc3)<ne<(ns, ng) is satisfied.

Abstract: A semiconductor optical integrated circuit includes: a semiconductor substrate; a light reflecting portion and a gain region, on the semiconductor substrate; a first optical waveguide connecting the reflecting portion and the gain region; and a second optical waveguide in conjunction with the first optical waveguide and having a larger optical absorptance than the first optical waveguide.

Abstract: The present invention relates to laser diodes with single mode emission at high output powers, as well as to structures and processes facilitating simple manufacture of such a devices. The invention includes a semiconductor laser (10) with a semiconductor substrate (11), a laser layer (13) arranged on the semiconductor substrate, an array of waveguide ridges (18) arranged at a distance from the laser layer, and several strip-shaped lattice structures (23) arranged on the flat surface between the waveguide ridges. The lattice structure (23) is formed on an insulating or barrier layer (26) at a distance from the laser layer above the laser layer (13). Processes for the production of such a semiconductor laser are also disclosed.

Abstract: A laser diode device of package not greater than 5.6 mm, having an automatic power control circuit directly mounted in a heat sink (or a submount) inside the metal cap thereof to substitute for an external circuit board for driving by voltage instead of current.

Abstract: A laser system outputs a laser light which is directed toward an object. The laser light has a frequency corresponding to the sympathetic or natural vibration frequency of molecules forming the object. The laser light is controlled so that in response to interaction with the object, the laser light forces the molecules of the object to vibrate at their sympathetic or natural vibration frequency thereby causing a thermal resistance of the object to increase whereupon a flow of thermal energy through the object is obstructed.

Abstract: A semiconductor laser apparatus includes a semiconductor laser element, a lead frame on which the semiconductor laser element is mounted, and an enclosure attached to the lead frame. When a direction in which a main beam is emitted from the semiconductor laser element is defined as forward, the lead frame has a reference surface serving as a reference for the semiconductor laser element in a forward or backward direction of the main beam, behind a portion where the semiconductor element is mounted.

Abstract: A glass fiber (22) has a core (24) provided with Raman laser effect particles (28) embedded in a glass matrix (30), with glass cladding (26) around the core. The refractive index of the glass matrix (30) is matched to that of the Raman laser effect particles (28) so as to avoid scattering. It is not necessary to have a single crystal of Raman laser material to create a laser effect in the glass fiber. A length of fiber in the order of meters or tens of meters can produce optical laser light. It is possible to have a single fiber (22) emit laser light at different frequencies due to Stokes and Anti-Stokes emissions. A simple laser device can therefore produce several colors of laser beams.

Abstract: A directly pumped, un-sensitized, holmium, quasi-two level fiber laser is disclosed that is doped with Holmium active ions between 0.1 and 2.0 percent by atomic weight. This yields greater energy efficiency from the laser because up-conversion losses are minimized, mismatches created by sensitizer ions are eliminated by having no sensitizer ions, and thermal loading of the fiber medium of the laser is thereby reduced. In addition, the pump ratio of the fiber laser is 0.9 which yields a very low quantum defect. The low doping percentage of holmium active ions also eliminates any absorption of its own energy because the power of the diode pumping source is sufficient to cause the laser to reach transparency.

Abstract: A laser gain device (10) holds a laser slab (60) which is pumped by pump energy from at least one diode array assembly (24). An angle at which pump energy from the diode array assembly (24) impinges the laser slab (60) is adjustable via angle adjustment means. The laser slab (60) is mounted between edge bars (62, 64) which have laser slab spacers (84) extending therethrough, allowing laser slabs (60) of different widths to be mounted within the laser gain device (10). One or more pump energy shields (88, 90) are used to control the amount of pump energy entering the laser slab (60), and cooling liquid conduits (100) are provided throughout components of the laser gain device (10), serving to conductively cool a heat shield (12).

Abstract: A wavelength conversion apparatus in which output direction of a wavelength-converted laser beam, having a wavelength converted by a nonlinear optical crystal and emitted through an output-window, can be brought close to the direction of optical axis of the laser beam passing through the nonlinear optical crystal. In addition, axial deviation of the wavelength-converted laser beam converted by the nonlinear optical crystal and emitted through an output-window, can be reduced when the position of the nonlinear optical crystal is moved. The output facet of the nonlinear optical crystal is inclined at Brewster's angle with respect to the wavelength-converted laser beam. An output-window of a case containing the nonlinear optical crystal has a prism form in which the distance between a laser beam input facet and a laser beam output facet of the output-window is reduced along a direction in which the wavelength-converted laser beam, emitted from the nonlinear optical crystal, inclines.

Abstract: External cavity optical transmitters are disclosed which include a gain chip and a mirror that define an optical cavity. The transmitters further include a modulator operated at or near the same temperature as the gain chip. In some examples, the optical transmitters are temperature controlled to optimize the efficiency and wavelength stability thereof, while maintaining acceptable chirp performance of the modulator. In some examples, the optical transmitters include an electro-optic module disposed within the optical cavity to change the path length thereof so that the efficiency and wavelength stability of the transmitter is optimized.