Abstract: In a semiconductor laser, at least one temperature sensor is disposed directly on or integrated in a semiconductor laser chip for measuring an operating temperature. Precisely and/or locally solved measurement of the operating temperature of the laser are possible. One or more temperature sensors may be placed and fastened directly onto the laser chip or in a hole of the laser chip by welding, especially with Nd-YAG-laser light or light with similar characteristics. Fine equalization of temperature may be carried out, for example, by Peltier elements, components of the Peltier elements being mounted directly onto the laser chip. A cascaded arrangement of thermoelements and Peltier elements on a laser chip is also provided for.

Abstract: A quantum dot active region is disclosed in which quantum dot layers are formed using a self-assembled growth technique. In one embodiment, growth parameters are selected to control the dot density and dot size distribution to achieve desired optical gain spectrum characteristics. In one embodiment, the distribution in dot size and the sequence of optical transition energy values associated with the quantum confined states of the dots are selected to facilitate forming a continuous optical gain spectrum over an extended wavelength range. In another embodiment, the optical gain is selected to increase the saturated ground state gain for wavelengths of 1260 nanometers and greater. In other embodiments, the quantum dots are used as the active region in laser devices, including tunable lasers and monolithic multi-wavelength laser arrays.

Abstract: A multiple reflectivity band reflector (MRBR) includes a stack of dielectric layers, arranged so that the reflector has a reflectivity profile comprising a plurality of reflectivity bands, e.g. at least first and second wavelength bands with reflectivity above a lasing threshold reflectivity, separated by a third wavelength band between the first and second wavelength bands having reflectivity below the lasing threshold reflectivity. A laser having at least a first mirror and an MRBR as the second mirror has a laser cavity, at least a portion of which is defined by the first mirror and the MRBR. An active region located within the laser cavity contains a material that is capable of stimulated emission at one or more wavelengths in the first and second wavelength bands. The gain spectrum of the laser is adjusted to select one of the first and second wavelength bands, thereby providing for lasing at a wavelength within the selected wavelength band. The laser may be, e.g.

Abstract: A quantum dot vertical cavity surface-emitting laser has a low threshold gain. Top and bottom mirrors have a low mirror loss, with at least one of the mirrors being laterally oxidized to form semiconductor/oxide mirror pairs. In one embodiment, mode control layers reduce the optical field intensity in contact layers, reducing optical absorption. In one embodiment, delamination features are included to inhibit the tendency of laterally oxidized mirrors from delaminating.

Abstract: An optical device structure includes a first substrate structure and a second substrate structure. The first substrate structure includes a first substrate, at least an active region formed on the first substrate, and at least a first electric connector portion provided corresponding to the active region for injecting a current into or applying a voltage to the active region. The second substrate structure includes a second substrate, and at least a second electric connector portion formed on the second substrate corresponding to the first electric connector portion. The first and second substrates are bonded to each other using an anisotropic electrically-conductive adhesive containing electrically-conductive particles and having an elctrically-conductive characteristic only in a direction perpendicular to the first and second substrates, such that the corresponding first and second electric connector portions on the first and second substrates are electrically connected to each other.

Abstract: A method for fabricating a buried semiconductor laser device including the steps of: forming a mesa structure including a bottom cladding layer, an active layer and a top cladding layer overlying an n-type semiconductor substrate; and forming a current confinement structure by growing a p-type current blocking layer and an n-type current blocking layer on each side surface of the mesa structure and on a skirt portion extending from the each side surface, the p-type current blocking layer being fabricated by using a raw material gas containing a group III element gas and a group V element gas at a molar ratio between 60 and 350 inclusive. In this method, the semiconductor laser device including the current confinement structure with the specified leakage current path width can be fabricated with the excellent reproducibility.

Abstract: An apparatus for removing heat from a lasing medium of a solid-state laser assembly is provided that comprises a working fluid and at least one condensation surface defined by a housing in which at least a portion of the lasing medium is housed. The apparatus further comprises a coolant circuit and a wick disposed to distribute the working fluid in a liquid state over at least a portion of an outer surface of the lasing medium and to capture working fluid condensing upon the at least one condensation surface. During use, the wick distributes the working fluid in a liquid state over the at least a portion of the outer surface of the lasing medium. During contact with the at least a portion of the outer surface of the lasing medium, the working fluid evaporates and removes heat from the lasing medium. The working fluid in a vapor state contacts the at least one condensation surface, transfers heat to the at least one condensation surface, and condenses on the at least one condensation surface.

Abstract: A semiconductor laser device includes a stacked structure. The stacked structure includes a first electrode, a substrate of a first conductivity type on the first electrode, a first cladding layer of the first conductivity type, an active layer, a second cladding layer of a second conductivity type opposite the first conductivity type, an insulating layer, and a second electrode. The second cladding layer includes at least first and second portions having thickness different from each other. The first portion is thicker than the second portion. The insulating layer is deposited on the second cladding layer but not on the first portion. The second electrode is electrically connected to the first portion. A product of a reciprocal of layer thickness and heat conductivity of the insulating layer is smaller than 4×108 W/(m2K).

Abstract: In order to improve a laser amplifying system comprising a solid-state member having a laser-active medium, a radiation field system determined by an optical guide means for the radiation field and an actively switchable, optical switching element arranged in the radiation field system for influencing the losses in the radiation field system in such a manner that this is suitable for low-amplification laser-active media, it is suggested that the solid-state member be designed like a thin plate, the radiation field system comprise an incoming branch and an outgoing branch which are coupled to one another, on the one hand, and between which, on the other hand, an amplifying radiation field is provided which is formed from a plurality of intermediate branches which extend between two optical beam reversing elements and, for their part, all penetrate the solid-state member in a direction transverse to its flat sides and within an active volume area, and that the active volume area have in directions transverse to

Abstract: To drive a single-mode laser device using a differential-pair output stage, collector terminals of transistors forming the differential-pair must be maintained at a predetermined potential. Since the potential dropped across the laser device is only about 1V, a Schottky diode connected between a cathode of the laser device and a second supply rail raises the cathode about 0.5V above the voltage of the second supply rail.

Abstract: A monitored laser system has a laser having a first mirror; an exit mirror, at least a portion of a laser cavity defined by the first mirror and the exit mirror; and an active region located in the laser cavity, the active region containing a material that is capable of stimulated emission at one or more wavelengths of laser light within a tuning range of the laser. A multiple reflectivity band reflector (MRBR) is coupled to at least a portion of laser light emitted from the laser and transmits filtered laser light. The MRBR has a plurality of layers of material arranged in parallel such that the reflector has a plurality of reflectivity peaks within the tuning range, each reflectivity peak separated from neighboring reflectivity peak by a reflectivity trough having a trough minimum, said reflectivity peaks characterized by a peak profile and said trough minima between said reflectivity peaks characterized by a trough profile.

Abstract: A multiple reflectivity band reflector (MRBR) includes a stack of dielectric layers, arranged so that the reflector has a reflectivity profile comprising a plurality of reflectivity bands, e.g. at least first and second wavelength bands with reflectivity above a lasing threshold reflectivity, separated by a third wavelength band between the first and second wavelength bands having reflectivity below the lasing threshold reflectivity. A laser having at least a first mirror and an MRBR as the second mirror has a laser cavity, at least a portion of which is defined by the first mirror and the MRBR. An active region located within the laser cavity contains a material that is capable of stimulated emission at one or more wavelengths in the first and second wavelength bands. The gain spectrum of the laser is adjusted to select one of the first and second wavelength bands, thereby providing for lasing at a wavelength within the selected wavelength band. The laser may be, e.g.

Abstract: A monitored laser system includes a laser with a first mirror and an exit mirror. The laser also has a laser cavity defined at least in part by the first mirror and the exit mirror. Within the laser cavity is an active region that contains material that is capable of stimulated emission at one or more wavelengths such that laser light is emitted from the laser. A power source is coupled to the active region. A multiple reflectivity band reflector (MRBR) is coupled to at least a portion of the emitted laser light. The MRBR has at least first and second wavelength bands with reflectivity above a particular reflectivity separated by at least a third wavelength band having reflectivity below the particular reflectivity. A first photodiode is coupled to at least a portion of the filtered laser light and produces an output based on the amount and wavelength of light received.

Abstract: The invention relates to a method of tuning a laser, comprising the steps of: providing a laser beam to an external cavity, the laser beam traveling through material along a path between a cavity end element and a tuning element, the path having an optical path length, selecting at least one mode of the laser by introducing a dispersion element in the path of the laser, rotating the tuning element about a pivot axis theoretically defined by the intersection of the surface planes of the cavity end element, the dispersion element and the tuning element to tune the laser, changing the optical path length of the path in order to at least partly compensate a shift between the real position of the pivot axis and the theoretically defined position.

Abstract: In an intersubband light emitter, at least two injection/relaxation (I/R) regions contiguous with the same RT region have different doping levels. Preferably, one I/R region has a doping level that is at least 100 times lower than that of the other I/R region. In one embodiment, one I/R region is undoped, whereas the other I/R region is doped.

Abstract: There is disclosed an improved semiconductor laser device (10). Previous high power (greater than a few hundred milliwatts output) semiconductor lasers suffer from a number of problems such as poor beam quality and low brightness. The invention therefore provides a semiconductor laser device (10) including at least one portion which has been Quantum Well Intermixed (QWI) and means for providing gain profiling within an active portion of the device (10). In a preferred implementation the device (10) provides a Wide Optical Waveguide (WOW).

Abstract: In a semiconductor laser device provided with a semiconductor laser element for outputting a laser beam having a plurality of oscillation longitudinal modes at a stimulated Brillouin scattering threshold or less, a submount formed by diamond and set between the semiconductor laser element and a carrier each configured to enable a highly efficient transfer of heat between the semiconductor laser device components.

Abstract: During assembly of a transmitter optical subassembly (TOSA), an alignment in Z-direction between a fiber stub array (FSA) and a VCSEL array is performed first, then an alignment in X-Y direction is performed. A rough pre-alignment in X-Y direction may also be performed prior to the alignment in Z-direction. A vertical cavity surface emitting laser (VCSEL) array may be hermetically sealed using a lens assembly or by using a separate lid assembly. The hermetic sealing and attaching of different components may be achieved by laser welding and/or soldering or any other suitable method.

Abstract: A quantum cascade laser comprising two electrodes (10, 18) for applying an electric control field and a waveguide placed between the two electrodes and which comprises: a gain region (14) consisting of several layers (20) which each comprise alternating strata (22) of a first type each defining a quantum barrier and strata (24) of a second type each defining a quantum well, and two optical confinement layers (12, 16) placed on each side of the gain region (14). According to the invention, each layer (20) of the gain region (14) is arranged so that the active region has three subbands, the potential differences between them being such that the transition of an electron between the two furthermost emits an energy (EGH, EHJ) corresponding to that needed for the emission of two optical phonons.

Abstract: A plurality of quantum dots are distributed dispersedly on the principal surface of a substrate comprising a first semiconductor. A cover layer comprising a second semiconductor is formed on a virtual plane on which the quantum dots are distributed. A barrier layer is disposed on the virtual plane at least in an area not disposed with the quantum dots. The barrier layer comprises a third semiconductor or insulator having a band gap wider than band gaps of the first and second semiconductors. A semiconductor device is provided which can prevent an injection efficiency of carriers into quantum dots.