Abstract: A core of an optical waveguide and a core of a waveguide type optical device are adjacently disposed, and a layer is continuously formed at one end of the core of the waveguide type optical device, wherein an effective refractive index of the layer decreases toward a long axis direction of the optical waveguide stripe.

Abstract: A method and apparatus for spatial mode selection of planar waveguide and thin slab lasers in the laser's large cross section size direction. The planar laser has a small cross section size direction orthogonal to a major axis thereof and a large cross section size direction orthogonal to the small cross section size direction and to the major axis. A planar reflector is disposed at one end of the planar laser, the planar reflector having a reflecting surface which is arranged orthogonally to the major axis and parallel to both the small and large cross section size directions of the laser. A Bragg grating is disposed in the optical track of the laser, the Bragg grating having a grating vector which is arranged in the plane normal to said small cross section size direction and at the angle between 0° and 90° to said large cross section size direction for suppression of higher order optical modes in said large cross section size direction.

Abstract: Semiconductor laser diodes, particularly high power ridge waveguide laser diodes, are often used in opto-electronics as so-called pump laser diodes for fiber amplifiers in optical communication lines. To provide the desired high power output and stability of such a laser diode and avoid degradation during use, the present invention concerns an improved design of such a device, the improvement concerns a method of suppressing the undesired first and higher order modes of the laser which consume energy and do not contribute to the optical output of the laser, thus reducing it's efficiency. This novel effect is provided by a structure comprising CIG—for Complex Index Guiding—elements on top of the laser diode, said CIG being established by fabricating CIG elements consisting of one or a plurality of layers and containing at least one layer which provides the optical absorption of undesired modes of the lasing wavelength.

Abstract: To provide a laser irradiation apparatus which performs alignment of an irradiated object and emits a laser beam precisely, a laser irradiation method, and a manufacturing method of a TFT with high reliability with the use of a method for precisely targeting a desired irradiation position of the laser beam. A substrate with marker is mounted on a stage formed using a material which transmits infrared light; a marker, which is provided in the substrate with marker mounted on the stage, is detected using a camera capable of sensing infrared light, and a position of the stage is controlled; a laser beam is emitted from a laser oscillator; the laser beam emitted from the laser oscillator is processed into a linear shape by an optical system, and the substrate with marker mounted on the stage is irradiated with the laser beam.

Abstract: A structure includes a photonic crystal layer which has a first member having a first refractive index and having a surface with a plurality of holes periodically arranged therein, and includes a low-refractive-index layer adjacent to the photonic crystal layer and having a second refractive index that is lower than the first refractive index. The relative refractive index difference between the first refractive index and the second refractive index is 0.10 or lower. Third members having a third refractive index that is higher than 1.0 are disposed in the holes.

Abstract: A structure includes a photonic crystal layer including a first member having a high refractive index in which a plurality of holes are periodically arranged, and a second member having a low refractive index. A third member is disposed on the first member. The third member has a refractive index higher than 1.0 and lower than the refractive index of the first member. The holes of the photonic crystal layer have a depth in the range of 20% to 80% of the thickness of the first member.

Abstract: A surface-emitting laser includes reflectors. One of the reflectors has multiple layers including one or more high-refractive-index layers and one or more low-refractive-index layers which are alternately stacked. At least one of the low-refractive-index layers includes a first region containing aluminum oxide and a second region surrounding the first region. A boundary between the first and second regions is positioned within a region where laser light is emitted. The reflectance of the multilayer reflector is higher in a portion including the first region than in a portion including the second region.

Abstract: An object of the present invention is obtaining a semiconductor film with uniform characteristics by improving irradiation variations of the semiconductor film. The irradiation variations are generated due to scanning while irradiating with a linear laser beam of the pulse emission. At a laser crystallization step of irradiating a semiconductor film with a laser light, a continuous light emission excimer laser emission device is used as a laser light source. For example, in a method of fabricating an active matrix type liquid crystal display device, a continuous light emission excimer laser beam is irradiated to a semiconductor film, which is processed to be a linear shape, while scanning in a vertical direction to the linear direction. Therefore, more uniform crystallization can be performed because irradiation marks can be avoided by a conventional pulse laser.

Abstract: Single longitudinal mode solid-state laser comprises solid-state laser and single-mode optical fiber, which Bragg grating is written on, as an external cavity. In one embodiment, the multimode laser is coupled from solid-state laser by lens system into external cavity which includes the optical fiber with Bragg grating written on. In the other embodiment, the multimode laser is coupled from solid-state laser directly into the external cavity which includes lensed optical fiber with Bragg grating written on. The Bragg grating selects lasing wavelength and discriminates against lasing of the other longitudinal modes in the multimode gain region. The solid-state laser with fiber Bragg grating external cavity generates single longitudinal mode laser with narrow spectrum and high side mode suppression ratio. The method is very simple and cost-effective.

Abstract: A diode laser system having a diode amplifier member with a large transverse gain area. The diode amplifier member includes an amplifying medium for amplifying a number of spatial modes of a spatial light distribution. The laser system further includes a number of passive reflective members forming a laser cavity which includes at least a part of the diode amplifier member, each of the passive reflective members being adapted, during operation, to reflect light at least partially into the amplifying medium. The passive reflective members are adapted, during operation, to induce, via the light reflected by them, a self-induced dynamic gain and refractive index grating in the diode amplifier member, the dynamic gain and refractive index grating selecting one of said spatial modes and suppressing at least a part of the remaining spatial modes of the spatial light distribution.

Abstract: In one exemplary embodiment of the invention, a method is employed that is directed to forming a resonant reflector on an optoelectronic device, such as a semiconductor laser for example. The exemplary method involves depositing a first material layer on the top layer of the optoelectronic device, where the first material layer having a refractive index and a thickness of about an odd multiple of a quarter of a wavelength to which the optoelectronic device is tuned. A patterned region is then created that extends at least partially into the first material layer. Selected patterned regions are at least partially filled with a second material that has a refractive index that is greater than the refractive index of the first material layer. Finally, a third layer, having a refractive index greater than the refractive index of the first material layer, is deposited immediately adjacent the first material layer.

Abstract: An external cavity laser may be swept rapidly in frequency and cavity length to prevent formation of modes providing improved spectral response and light characteristics.

Abstract: A surface emitting semiconductor laser includes a laminate of semiconductor layers emitting multimode laser light, and a block member blocking light of a specific mode among the multimode laser light emitted from the laminate.

Abstract: A mode locking device of fiber laser includes a bar structural body, having a central hollow region, extending along a reference line of the bar structural body. The central hollow region has two ends coupled with two collimators on a fiber laser loop. A polarization dependent isolator is disposed within the central hollow region of the bar structural body such that the laser ca propagate only in one direction. Several rotors are disposed within the central hollow region of the bar structural body. Each rotor has a protruding piece, for rotating the rotor along the reference line. The laser beam travels along the reference line and passes through the rotors. Several retardation waveplates are disposed on the rotator structures and can be rotated together with the rotors. Each waveplate is adjusted to an angle, such that the laser can be mode-locked automatically.

Abstract: Provided is a system of computing and rendering a nature of a chemical bond based on physical, Maxwellian solutions of charge, mass, and current density functions of hydrogen-type molecules and molecular ions. The system includes a processor for processing Maxwellian equations representing charge, mass, and current density functions of hydrogen-type molecules and molecular ions and an output device in communication with the processor for displaying the nature of the chemical bond.

Abstract: A method of controlling the state of polarization of an optical signal includes injecting the optical signal into a laser diode and matching the wavelength of the optical signal to a longitudinal mode of the laser diode. A stabilizer signal can also be injected in to the laser diode. The wavelength of the stabilizer signal is matched a first longitudinal mode of the laser diode a longitudinal mode of the laser diode to the optical signal.

Abstract: According to an aspect of the present invention, a nitride semiconductor laser device includes a nitride semiconductor active layer, and a stripe-shaped waveguide for guiding light generated in the active layer. At least one pair of light-absorbing films are provided in at least local regions on the opposite sides of the stripe-shaped waveguide, to reach a distance within 0.3 ?m from the waveguide. According to another aspect of the present invention, a gan-based semiconductor laser device includes first conductivity type semiconductor layers, a semiconductor active layer and second conductivity type semiconductor layers stacked sequentially. The laser device further includes a ridge stripe provided to cause a refractive index difference for confinement of light in a lateral direction crossing a longitudinal direction of a cavity, and a current-introducing window portion provided on the ridge stripe.

Abstract: A beam shaping optical arrangement combines three incoming laser beams that are mutually laterally offset in two orthogonal directions (X and Y), including an incoming first central laser beam and second and third incoming beams laterally offset in the X direction on either side of the central beam, into one outgoing combined laser beam. The arrangement includes two lateral displacement optical units though which the laterally offset incoming beams are transmitted and that laterally displace the two laterally offset incoming beams along the X direction towards the incoming central beam but which do not laterally offset the incoming central beam.

Abstract: As a composite laser rod capable of satisfying the positional stability and output stability of a laser beam, a laser rod in which a laser active element is doped is intimately inserted into a hollow portion of a non-doped ceramic pipe that has a crystal structure the same as the laser rod followed by baking so as to remove a gap and strain at an interface between the laser rod and the ceramic pipe after the baking further followed by polishing a surface of the ceramic pipe to form a ceramic skin layer, and thereby a composite laser rod is formed. In the composite laser rod, an influence due to fluctuation in the cooling capacity of cooling water or a heat sink is averaged by a non-doped skin layer, temperature fluctuation of the laser rod is suppressed, and an influence of vibration from the cooling water or a cooling fan can be suppressed.

Abstract: The invention relates to optical communication devices, light emission devices and optical communication methods. Aspects of the present invention provide methods and devices enable provision of modulated output optical signals without providing modulation of total photon populations of cavities of associated lasers. Such avoids or minimizes bandwidth restrictions associated with conventional methods or devices which modulate total photon populations within cavities of lasers. One aspect of the invention includes an optical communication method including providing a data signal comprising data to be communicated and emitting light using a laser. The method further includes modulating the laser across a lasing mode transition responsive to the data signal. The emitting further includes emitting the light during a plurality of lasing modes of the laser to communicate the data responsive to the modulating.

Abstract: A device for generating blue or green laser light, comprising an infrared high power semiconductor laser or an infrared high power semiconductor laser bar or array, a diffractive optical device, and an optical device utilizing a non-linear crystal to generate the blue or green laser light.

Abstract: A spatial filter adapted to increase the angular spread of non-conjugated energy in a beam and suppress this energy to improve the efficiency of a phase conjugate system. In the illustrative embodiment, the filter includes first and second lenses and an aberrator to increase the angular spread. In the specific embodiment, an opaque plate, with a pinhole aperture therethrough, is sandwiched between the lenses to suppress the non-conjugated energy. The aberrator may be implemented with an amplifier or other suitable mechanism. Likewise, the aperture may be replaced with a highly angle-selective thick Bragg grating or other suitable arrangement. A phase conjugate master oscillator/power amplifier laser architecture is also disclosed.

Abstract: A method is provided for seeding laser system (10) for single longitudinal mode oscillation. The method includes coupling laser system (10) to be seeded for single mode output to a seed laser radiation source (12). Next, the frequency capture range (44) and spacing (46) of the axial modes (42) of the cavity (24) of the laser system (10) are determined. A seed spectrum (36) is then generated from the seed laser radiation source (12) with a bandwidth (40) corresponding to the axial mode spacing (46). The seed spectrum (36) includes a comb of discrete frequency components (38) with one or more of the discrete frequency components (38) being within the frequency capture range (44) of at least one of the axial modes (42). The seed spectrum (36) is then injected into the cavity (24) such that at least one of the axial modes (42) oscillates with the seed radiation.

Abstract: A semiconductor laser diode capable of achieving an improvement in kink level and an improvement in catastrophic optical damage (COD) level. The semiconductor laser diode includes a first-conductivity type semiconductor substrate, a first-conductivity type clad layer formed over the substrate, an active layer formed over the first-conductivity type clad layer, a second-conductivity type clad layer formed over the active layer, and provided with a ridge, and a light confining layer formed on the second-conductivity type clad layer, and made of a first-conductivity type semiconductor material, the light confining layer including higher-order mode absorption layers having an energy band gap lower than optical energy produced in the active layer, and refractive index control layers having a refractive index lower than that of the higher-order mode absorption layers. The higher-order mode absorption layers and refractive index control layers are laminated in an alternate manner.

Abstract: Disclosed is a side pumping type DPSS (Diode Pumped Solid-State) laser having a high efficiency of pumping light together with a large output of the laser power. The DPSS laser includes a first laser chip for generating a pumping light, a second laser chip provided at a predetermined degree to be slightly slanted, although being parallel with the first laser chip, so as to avoid a contact with the pumping light, a first and second focusing lens for focusing the pumping lights, and a side pumping medium for forming the focused pumping lights in a beam mode so as to output as a lasing light.

Abstract: Using lateral physical modulation, the optical properties of VCSELs can be stabilized and controlled by spatially varying the characteristics of the device material. This results in stabilization of the linewidth, the numerical aperture, the near and far field, as a function of bias and temperature. A VCSEL includes a substrate, an active region sandwiched between an upper and lower distributed Bragg reflector (DBRs), and electrical contacts. A light emission property e.g. the index of refraction, may be varied by patterning or texturing the surface of the substrate prior to growth of the epitaxial DBR layers or at least one layer of either the upper or lower DBRs, or by inserting a non-planar layer.

Abstract: A diode laser system providing a high-power laser beam with good spatial coherence, which can be focused to a small spot size over long distances and which has a good pointing stability. The laser system comprises a laser diode (301) adapted to emit a first light beam, where the first light beam comprises a plurality of spatial modes, selection means (304) adapted to select a predetermined part of the first light beam, and a reflector (306), where the laser diode and the reflector define a cavity and where the reflector is adapted to reflect the selected part of the first light beam back into the laser diode as a second light beam. The laser system is characterised in that the selection means is adapted to select a part of the first light beam corresponding to a spatial mode with a higher mode number than a spatial mode with maximum gain.

Abstract: Provided is a fiber grating laser for optical communication which can be used as a light source regardless of the occurrence of mode hopping. The laser module comprises a semiconductor optical amplifier device, an optical waveguide such as an optical fiber, and a diffraction grating such as a fiber grating. The semiconductor optical amplifier device has first and second end surfaces. The optical waveguide is optically coupled to the semiconductor optical amplifier device. The diffraction grating is optically coupled to the optical waveguide. The semiconductor optical amplifier device and the diffraction grating constitute an external cavity. An optical cavity length of the external cavity is in a range of 13 millimeters or more but 27 millimeters or less.

Abstract: The invention is directed to a photonic crystal defect structure for a vertical cavity surface emitting laser (VCSEL). In accordance with the invention, a set of holes is formed in a pattern with one or more missing holes forming a defect in the pattern of the photonic crystal, according to a proscribed depth, hole diameter, and pattern pitch which will insure operation in a single transverse mode.

Abstract: A method and apparatus for stabilizing the output of a mode-locked laser by monitoring the temporal behavior of the pulse train profile and controlling the laser cavity optical length and/or loss modulation frequency accordingly. A mismatch of the cavity optical length and the loss modulation frequency will yield a first characteristic noise condition on the laser beam pulse train when the optical length is too short for a given loss modulation frequency and a second, different noise condition when the optical length is too long. The laser beam is monitored and analyzed to determine which noise condition is present. The cavity optical length is adjusted accordingly by movement of one or more optical elements or by changing the index of refraction of one or more optical elements. In the alternative, or additionally, the loss modulation frequency can be adjusted to bring the laser back into mode lock.

Abstract: A method and apparatus for improving the beam quality of the emissions from a multimode gain medium such as a broad-stripe laser through the use of SBC techniques is provided. In order to achieve the desired beam quality without a significant reduction in output power, discrete lasing regions are formed across the gain medium using an etalon or similar device located within the SBC cavity.

Abstract: A vertical cavity surface emitting laser (VCSEL) in which a higher order lasing mode produces a Gaussian-like single mode far field beam intensity pattern. Such a VCSEL includes a protective surface deposition on a VCSEL structure, and phase filter elements on the surface deposition. The surface deposition and the phase filter elements implement an optical phase filter that induces optical path difference such that a single mode far field beam intensity pattern results when the VCSEL operates in a higher order lasing mode. The VCSEL can include structures that enhance a selected higher-order operating mode and/or that suppress unwanted operating modes.

Abstract: A chiral structure having an expanded adjustable reflection band to provide broadband tunability is provided. In the preferred embodiment, the chiral structure is implemented as a chiral fiber structure and comprises two or more sequential chiral fiber elements of different pitches, each having a tunable chiral defect generator. The pitches are selected such that the individual photonic band gaps of the elements are formed into one expanded reflection band such that at least one defect state can be formed and moved within the expanded reflection band by selectively activating and adjusting one or more of the tunable chiral defect generator. The tunable chiral defect generators may generate and control defect state(s) in the structure's spectral response by introducing chiral twists and/or spacing between the chiral elements, with the length of the spacings and angles of chiral twists being proportional to the position of the defect state(s) within the reflection band of the structure.

Abstract: The integrated-optics coupling component is designed to cooperate with a transverse multimode power laser diode (2) with semi-conductor to form a transverse multimode power laser. It comprises an input zone (4) connected to at least one output waveguide (6) by at least two adiabatic tapering zones (5). At least two filtering windows (7) form the inputs of the adiabatic tapering zones (5) at the end of a diffraction zone defined by the input zone. Reflecting elements, for example a Bragg grating (12), can be arranged on the output waveguide. An emitting face (3) being antiglare-treated, an extended laser cavity oscillating on a single predetermined mode is thus defined between a reflecting rear face (11) of the laser diode and the reflecting elements (12).

Abstract: There is provided a surface emitting semiconductor laser satisfying a requirement of making a transverse mode stable and having characteristics of high output power, low resistance, high efficiency, and high speed response and a method for manufacturing the surface emitting semiconductor laser. Five holes are formed on the top surface of an upper multilayer reflection film formed in the shape of a post by the use of a focused ion beam (FIB) processing unit. One hole is formed on the surface of an upper multilayer reflection film corresponding to the center position of a square current injection region which is about 8 ?m square and the remaining four holes are formed at the corners of the square current injection region, for example, at the positions about 2 ?m square away from the one hole to produce four light emitting spots.

Abstract: A compact single frequency, single-mode 1 ?m fiber laser with narrow linewidth (<10 kHz) and high output power (>2 mW) is formed with an oxide-based multi-component glass fiber doped with triply ionized rare-earth ytterbium ions and fiber gratings formed in sections of passive silica fiber and fused thereto. The multi-component glass supports higher doping concentrations than standard silica fiber, hence higher output power levels in short cavities. Formation of the gratings in passive silica fiber both facilitates splicing to other optical components and reduces noise thus improving linewidth.

Abstract: A tunable laser and laser tuning method, based on the interaction of a spectrally dependent beam distortion and a spatial filter within a laser cavity. One embodiment of this laser is an external cavity semiconductor laser in which broad tunability is obtained by the insertion of an acousto-optic tunable filter (AOTF) into the laser cavity such that the intra-cavity laser beam passes through the AOTF in zeroth order.

Abstract: Apparatus and method for integrating lasers and optics on glass substrates. An optical (e.g., laser) component formed from a glass substrate doped with a optically active lanthanides species with a plurality of waveguides defined by channels within the substrate. The laser component optionally includes a monolithic array of individual waveguides in which the waveguides form laser resonator cavities with differing resonance characteristics. Another aspect is directed toward pumping the laser wherein a superstrate waveguide cavity, or cladding, Ls positioned adjacent the substrate waveguide for supplying the latter with pump light. A closed crucible processing of optical waveguides on a glass substrate is also described. Waveguides are created by exposing a surface of the substrate to an ion-exchange solvent (e.g., a molten salt). A tightly sealed multi-part crucible is provided in order that gas does not leak in or out of the crucible during cooling or heating of the system.

Abstract: A high-power coherent array of Vertical Cavity Surface Emitter Lasers is described in which a plurality of Vertical Cavity Surface Emitting Lasers (VCSELs) are provided along with a structure which optically couples each of the VCSELs the plurality of VCSELs to one another by a predetermined amount to cause a coherent mode locking condition to occur. The coupling structure can be a beam cube, a plurality of smaller bean cubes, or a waveguide/grating system, for example. A reference source, or controlled coupling among the VCSELs, is used to phase lock the VCSELs to one another.

Abstract: A single longitudinal mode laser, such as a distributed feedback laser, that comprises a filter. The filter selectively attenuates wavelengths that are lower than the wavelength of the laser's dominant mode, such that when operating at extremes of temperature, the power of the gain peak does not become too great relative to the dominant mode of the laser.

Abstract: A semiconductor laser module including a semiconductor laser device having an integrated diffraction grating configured to output a multiple mode laser beam in the presence of a driving current, an optical fiber configured to guide the multiple mode laser beam to an output of the laser module, and an optical attenuation device configured to attenuate the multiple mode laser beam by an amount sufficient to provide a predetermined output power from the output of the laser module. The optical attenuation device may be an optical coupling lens offset from an optimum coupling position by an amount sufficient to provide the predetermined output power, or an optical attenuator interrupting the optical fiber and configured to attenuate the multiple mode laser beam by an amount sufficient to provide the predetermined output power.

Abstract: An object of the present invention is obtaining a semiconductor film with uniform characteristics by improving irradiation variations of the semiconductor film. The irradiation variations are generated due to scanning while irradiating with a linear laser beam of the pulse emission. At a laser crystallization step of irradiating a semiconductor film with a laser light, a continuous light emission excimer laser emission device is used as a laser light source. For example, in a method of fabricating an active matrix type liquid crystal display device, a continuous light emission excimer laser beam is irradiated to a semiconductor film, which is processed to be a linear shape, while scanning in a vertical direction to the linear direction. Therefore, more uniform crystallization can be performed because irradiation marks can be avoided by a conventional pulse laser.

Abstract: A subject of the invention is to reduce the temperature dependence of an etalon as a wavelength locker for a semiconductor laser device and so forth. Concretely, it is to restrict the lowering of the wavelength locking performance of the etalon dependent on the temperature variation. A means to solve the subject is the use of an air gap etalon. Concretely, the means is provided with a media plate and parallel plane plates on both sides of the media plate. The two parallel plane plates and the space between them constitute the air gap etalon.

Abstract: A semiconductor laser module has a Fabry-Perot type semiconductor laser device, an optical fiber, and first and second lenses. The tip of the optical fiber, on which the laser beam falls, is askew polished. The optical fiber is fixed in such a manner that the axis of the optical fiber makes an angle with respect to an optical axis of the laser beam. Coatings that avoid reflection are formed on the tip of the optical fiber, and on the first and second lenses.

Abstract: An apparatus and method for controlling the phase of a tunable laser is provided. Stabilization of the mode of a laser beam is provided as the laser is tuned to a target frequency. For one embodiment, a laser generates a reference beam and an output beam. The power of each of beam is measured by optical detectors, and a ratio thereof is utilized to detect when a mode hop occurs as the laser is coarsely tuned. The average of the pre and post mode hop ratios is utilized as a control setpoint while finely tuning the laser to the target frequency. Wavelength lockers, optical power dividers and optical detectors are utilized to determine power levels of the reference and output beams while also monitoring frequency characteristics thereof. A control unit utilizes the outputs from the wavelength locker to control the operation of the extended cavity laser during and after tuning.

Abstract: A distributed feedback laser device inhibiting beam coupling coefficient variation resulting from fabrication dispersion and improving fabrication yield. The distributed feedback laser device includes cladding layers provided on an InP substrate and located on both sides of an active layer and a diffraction grating having grating bars, different in refractive index from the cladding layers, in either cladding layer and extending in a direction perpendicular to a light emission direction at a prescribed pitch in the emission direction, as well as at least one light distribution control layer, located in the cladding layer, spaced from the diffraction grating and having the same composition as the diffraction grating.

Abstract: A high power diode laser system utilizes an external cavity to narrow the spectral width of a high power multimode diode laser to change the output power normally produced by the diode from a broad spectrum to a very narrow spectrum. The power output of the laser system is concentrated over a narrow spectral range which falls within the useable range for particular applications, such as optical pumping of noble gas samples for magnetic resonance imaging. The output of the diode is received by a collimating element which directs the light on a beam path to a diffraction grating which is oriented at an angle to the incident beam. A portion of the beam may be directed from the diffraction grating to provide useable output light, and a portion of the light incident on the grating is directed back to be focused on the diode to provide feedback to cause the diode to preferentially lase at the wavelength of the light that is fed back.

Abstract: Method of generating laser pulses using a semiconductor laser diode as a lasing amplification medium of an extended laser cavity are presented. Passive self-modulated mode-locked operation of the semiconductor laser diode is achieved by providing an above lasing threshold direct current input current to the semiconductor laser diode while the semiconductor laser diode is operational in a slightly misaligned extended laser cavity favoring the amplification of wavelengths shorter than a center wavelength of a continuous wave operational mode of the semiconductor laser diode at threshold.

Abstract: Semiconductor laser diodes, particularly high power ridge waveguide laser diodes, are often used in opto-electronics as so-called pump laser diodes for fiber amplifiers in optical communication lines. To provide the desired high power output and stability of such a laser diode and avoid degradation during use, the present invention concerns an improved design of such a device, the improvement in particular consisting in a way of suppressing the undesired first and higher order modes of the laser which consume energy and do not contribute to the optical output of the laser, thus reducing it's efficiency. Essentially, the novel effect is provided by a structure comprising CIG—for Complex Index Guiding—elements on top of the laser diode. These CIG elements consist of one or a plurality of layers and must contain at least one layer which provides the optical absorption of undesired modes of the lasing wavelength and preferably contains an insulating layer as a first contact layer to the semiconductor.

Abstract: A Fabry-Perot laser and a micro-actuator are utilized to provide continuous tuning over a range of wavelengths.