Abstract: Configurations for a photonics assembly and the operation thereof are disclosed. The photonics assembly may include multiple photonics dies which may be arranged in an offset vertical stack. The photonics dies may emit light, and in some examples, an optical element may be a detector for monitoring properties such as the wavelength of the light. The photonics dies may be arranged in a stack as a package and the packages may be stacked or arranged side by side or both for space savings. The PIC may include combining and/or collimating optics to receive light from the photonics dies, a mirror to redirect the light, and an aperture structure. The aperture structure may include a region which is at least partially transparent such that light transmits through the transparent region of the aperture structure. The aperture structure may include an at least partially opaque region which may be used for directing and/or controlling the light launch position.

Abstract: An applicator comprising multiple laser assemblies connected to a power supply and a controller that switches each pulse to a different one of the laser assemblies. Each laser assembly deposits a laser spot on the skin and the result is to produce a large ‘aggregate’ spot without requiring extra power or extra lasers. In one embodiment, each pulse serves as a trigger to switch the next pulse to the next laser assembly.

Abstract: The invention relates generally to cooling matter using laser emission, and in particular, to cooling perovskite materials using laser emission.

Abstract: An apparatus includes a laser diode, a heater arrangement, and a circuit. The laser diode is configured to facilitate heat assisted magnetic recording during a lasing state. The heater arrangement is positioned proximate the laser diode. The circuit electrically couples the laser diode and the heater arrangement in a parallel relationship. The circuit is configured to alternately operate the laser diode in a lasing state and a non-lasing state, and to activate the heater arrangement during the non-lasing state to warm a junction of the laser diode.

Abstract: Disclosed is a surface emitting laser device, including a substrate; a lower reflecting mirror provided on the substrate; an active layer provided on the lower reflecting mirror; an upper reflecting mirror provided on the active layer, including an emitting region, laser light being emitted from the emitting region, the upper reflecting mirror being formed by alternately laminating dielectrics, refracting indices of the dielectrics being different from each other; and an adjusting layer formed of semiconductor, provided in the emitting region between the active layer and the upper reflecting mirror, a shape of the adjusting layer in a plane parallel to a surface of the substrate including shape anisotropy in two mutually perpendicular directions.

Abstract: A device including one or more layers with lateral regions configured to facilitate the transmission of radiation through the layer and lateral regions configured to facilitate current flow through the layer is provided. The layer can comprise a short period superlattice, which includes barriers alternating with wells. In this case, the barriers can include both transparent regions, which are configured to reduce an amount of radiation that is absorbed in the layer, and higher conductive regions, which are configured to keep the voltage drop across the layer within a desired range.

Abstract: Disclosed are heterogeneous crystals for use in a laser cavity and methods of forming the crystals. A crystal can be a monolithic crystal containing regions that are based upon the same host material but differ from one another according to some material feature such that they can perform various functions related to lasing. Disclosed methods include hydrothermal growth techniques for the growth of differing epitaxial layers on a host. A host material can be doped in one region with a suitable active lasing ion and can be formed with another region that is undoped and can act as an endcap, a waveguide cladding layer, or a substrate to provide strength and/or contact to a heat sink. Regions can be formed with controlled thickness in conjunction. Following formation, a heterogeneous crystal can be cut, polished and coated with mirror films at each end for use in a laser cavity.

Abstract: A quantum cascade laser structure having a plurality of cascades each of which comprises a number of alternately arranged quantum wells and barriers of different thicknesses and heights, wherein at least one of the quantum wells and at least one of the barriers is under mechanical strain and the quantum wells and the barriers are coordinated such that the existing mechanical strains are largely compensated within one cascade, wherein each of the barriers comprise one or more barrier layers, wherein each cascade comprises a thinnest quantum well, a lowest barrier, a thickest quantum well, a highest barrier, and the highest barrier is followed by alternately arranged quantum wells and barriers.

Abstract: The invention relates to an external cavity wideband tunable laser with dual laser gain media coupled by a thin film filter. The laser comprises: a first laser gain medium, a first laser cavity end mirror arranged on the first laser gain medium, a first intracavity collimating lens, an active optical phase modulator, a tunable acousto-optic filter, an intracavity reflection mirror, an etalon and a total reflection mirror, which are all arranged sequentially inside the laser cavity. The laser further comprises a second laser gain medium, a second laser cavity end mirror arranged on the second laser gain medium, a second intracavity collimating lens, a thin film optical filter for coupling the output light beams emitted from the first laser gain medium and the second laser gain medium, a radio frequency signal source, pumping sources for the two laser gain media, an active optical phase modulator drive source and a laser drive control circuit.

Abstract: A device for transformation of concentrated solar energy including a photovoltaic cell and laser device, which includes a first reflecting mirror adapted for entry of a beam of solar rays and a second reflecting mirror adapted for an outlet of a laser beam, with the first reflecting mirror reflective on an outlet wavelength of the laser beam and transparent to a totality of a solar spectrum and the second reflecting mirror partially reflective on the wavelength of the laser beam, reflective in an interval of the solar spectrum which is absorbed and transparent in other wavelengths different to these, and at the outlet of the laser beam. The device includes a nucleus doped with substances for total or partial absorption of the solar spectrum and coatings.

Abstract: A CO2 gas laser device according to the present invention amplifies CO2 laser light that oscillates repeatedly in short pulses having a pulse width of 100 ns or less, and cools a CO2 laser gas which is excited by continuous discharge by circulating the CO2 laser gas by means of forced convection. Therein, an angle ? defined by the optical axis of the amplified CO2 laser beam and the flow direction of the CO2 laser gas caused by the forced convection is determined by both a discharge cross sectional area and a discharge length of a volume in which the CO2 laser gas is excited by discharge, whereby increasing the gain of pulsed laser to achieve pulsed laser light having an extremely high average output power.

Abstract: A quantum cascade laser includes a plurality of active layers, each of active layers including a first barrier layer, a first quantum well layer, a second barrier layer, a second quantum well layer, a third barrier layer, a third quantum well layer, and a fourth bather layer provided in this order along a predetermined direction; a plurality of injection layers; and a core layer having the active layers and the injection layers, the active layers and the injection layers being alternately provided along the predetermined direction to form a cascade structure. The first quantum well layer has a film thickness larger than a film thickness of the second quantum well layer. The second quantum well layer has the film thickness larger than a film thickness of the third quantum well layer. In addition, the second barrier layer has a film thickness smaller than a film thickness of the third bather layer.

Abstract: An optical device, a method of making a laser gain medium, and a method of suppressing parasitics in a laser device include a core region comprising a plurality of a first type of ions that absorb energy at a first wavelength and transfer the absorbed energy to a plurality of a second type of ions that lase at a second wavelength after receiving the transferred energy. A cladding region coupled to the core region comprising another plurality of the second type of ions that suppress parasitics in the optical device by absorbing energy of at least a transverse portion of the second wavelength that enters the cladding region.

Abstract: A laser beam combining and power scaling device and method. A first highly reflective mirror residing perpendicular to the first optical axis reflecting radiation emitted from the first laser head. A first Q-switch in alignment with the first optical axis interposed between the first highly reflective mirror and the first laser head. A second highly reflective mirror residing perpendicular to the second optical axis reflecting radiation emitted from the second laser head. The second Q-switch in alignment with the second optical axis is interposed between the second highly reflective mirror and the first laser head. A third optical axis is coincident with the first optical axis. A third highly reflective mirror residing perpendicular to the third optical axis in alignment therewith. The third optical axis may include a third diode pumped laser head and Q-switch. A beam splitter resides at the intersection of the axes.

Abstract: A main amplifier system includes a first reflector operable to receive input light through a first aperture and direct the input light along an optical path. The input light is characterized by a first polarization. The main amplifier system also includes a first polarizer operable to reflect light characterized by the first polarization state. The main amplifier system further includes a first and second set of amplifier modules. Each of the first and second set of amplifier modules includes an entrance window, a quarter wave plate, a plurality of amplifier slablets arrayed substantially parallel to each other, and an exit window. The main amplifier system additionally includes a set of mirrors operable to reflect light exiting the first set of amplifier modules to enter the second set of amplifier modules and a second polarizer operable to reflect light characterized by a second polarization state.

Abstract: A laser system having a cooling apparatus is disclosed. The laser system includes a resonator, a gain medium and multiple heat-absorbing discs. The resonator is formed by a first mirror and a second mirror. The gain medium, which is contained within the resonator, is collectively formed by a group of gain medium segments. Each of the gain medium segments is preferably in the shape of a cylindrical disc. The heat-absorbing discs are interleavely disposed among the gain medium segments to provide face cooling for the gain medium segments during the operation of the laser system.

Abstract: An active laser medium includes a metal nanoparticle and a shell surrounding the metal nanoparticle, the shell including a luminophor, wherein a luminescence spectrum of the luminophor overlaps with a peak of surface plasmon resonance of the metal nanoparticle.

Abstract: The different advantageous embodiments provide an apparatus and method comprising a substrate configured to increase an intensity of light at a desired wavelength. The substrate has a front side, a back side, and an outer edge. The substrate is configured to reflect the light received on the front side of the substrate. The substrate comprises ceramic. The substrate comprises a plurality of sections. The method and apparatus also comprise a material configured to attenuate the light passing between the plurality of sections. The material surrounds an edge of each section of the plurality of sections. The apparatus and method also comprise a cooling system configured to allow liquid nitrogen to be transmitted through the cooling system and receive heat generated in the substrate from the back side of the substrate.

Abstract: A laser beam combining and power scaling device and method. A first highly reflective mirror residing perpendicular to the first optical axis reflecting radiation emitted from the first laser head. A first Q-switch in alignment with the first optical axis interposed between the first highly reflective mirror and the first laser head. A second highly reflective mirror residing perpendicular to the second optical axis reflecting radiation emitted from the second laser head. The second Q-switch in alignment with the second optical axis is interposed between the second highly reflective mirror and the first laser head. A third optical axis is coincident with the first optical axis. A third highly reflective mirror residing perpendicular to the third optical axis in alignment therewith. The third optical axis may include a third diode pumped laser head and Q-switch. A beam splitter resides at the intersection of the axes.

Abstract: An amplifying optical fiber includes a core containing oxides of elements selected from the group consisting of silicon, germanium, phosphorus, bismuth, aluminum, gallium with a concentration of bismuth oxide of 10-4-5 mol %, a total concentration of silicon and germanium oxides of 70-99.8999 mol %, a total concentration of aluminum and gallium oxides of 0.1-20 mol % wherein both aluminum and gallium oxide are present and a ratio of aluminum oxide to gallium oxide is at least two, and a concentration of phosphorus oxide from 0 to 10 mol %, and provides a maximum optical gain at least 10 times greater than the nonresonant loss factor in the optical fiber. An outside oxide glass cladding comprises fused silica. The core has an absorption band in the 1000 nm region, pumping to which region provides an increased efficiency of power conversion of pump light into luminescence light in the 1000-1700 nm range.

Abstract: A light emitting device and the fabrication method includes forming one or more light emitting modules on a substrate. The light emitting module receives an alternating current input and has at least two micro diodes. Each micro diode has at least two active layers and is electrically connected by a conductive structure so as to allow the active layers of the micro diodes to alternately emit light during positive and negative cycles of the alternating-current input.

Abstract: A solid-state gain element including a thin doped region in which an optical signal propagates through the thin doped region at a large angle with respect to the normal to the thin doped region, reflects at a boundary of the thin doped region, and passes through the thin doped region again. An optical pump beam propagates through the thin doped region also at a large angle with respect to the normal to the thin doped region. In one example, the gain element and source of the pump beam are configured such that there is total internal reflection of the pump beam at the boundary of the thin doped region for a second pumping pass through the thin doped region. In another example, an elliptically symmetric laser beam is used to create a circularly symmetric gain region in the thin doped region.

Abstract: Current may be passed through an n-doped semiconductor region, a recessed metal semiconductor alloy portion, and a p-doped semiconductor region so that the diffusion of majority charge carriers in the doped semiconductor regions transfers heat from or into the semiconductor waveguide through Peltier-Seebeck effect. Further, a temperature control device may be configured to include a metal semiconductor alloy region located in proximity to an optoelectronic device, a first semiconductor region having a p-type doping, and a second semiconductor region having an n-type doping. The temperature of the optoelectronic device may thus be controlled to stabilize the performance of the optoelectronic device.

Abstract: An optical apparatus comprising a gain medium exhibiting polarisation dependent absorption along two axes, the gain medium having a weakly absorbing axis and a strongly absorbing axis, an optical pump source arranged to direct pump light towards a first face of the gain medium such that the pump light entering the gain medium has a component of its polarisation parallel to the weakly absorbing axis, a polarisation modifying apparatus and one or more reflectors which are together arranged to modify the polarisation of pump light which exits the gain medium through a second face of the gain medium, and to direct the pump light with modified polarisation back towards said second face of the gain medium.

Abstract: A two-beam semiconductor laser device 10 includes: a two-beam semiconductor element LDC having a first and a second semiconductor laser elements LD1 and LD2 that can be driven independently and that are formed integrally on a substrate; and a submount 63 having, mounted on a front part thereof, the two-beam semiconductor laser element LDC with the light-emitting face thereof directed forward and having a first and a second electrode pads 64 and 65 connected to electrodes 61 and 62 of the first and second semiconductor laser element LD1 and LD2 by being kept in contact therewith. The first and second electrode pads 64 and 65 are formed to extend farther behind the two-beam semiconductor laser element LDC, and wires 14 and 16 are wire-bonded behind the two-beam semiconductor laser element LDC.

Abstract: A laser projector includes a green laser, a two-wavelength laser, a PBS, a collimator lens, a two-axis galvanometer mirror, a group of lenses, and a screen. The green laser emits a green laser beam. The two-wavelength laser emits red and blue laser beams. The PBS is provided at the position where respective optical paths of laser beams emitted from respective lasers cross each other to cause these optical paths to coincide with each other.

Abstract: A laser medium comprises a solid-state host material and dopant species provided within the solid-state host material. A first portion of the dopant species has a first valence state, and a second portion of the dopant species has a second valence state. In an embodiment, a concentration of the first portion of the dopant species decreases radially with increasing distance from a center of the medium, and a concentration of the second portion of the dopant species increases radially with increasing distance from the center of the medium. The laser medium further comprises impurities within the solid-state host material, the impurities converting the first portion of the dopant species having the first valence state into the second portion of dopant species having the second valence state.

Abstract: Provided is a laser apparatus including: a DFB fiber laser 40 including, as an amplitude medium, a rare earth doped silica optical fiber codoped with a high concentration of aluminum; an optical feedback path 50 formed by a ring-shaped optical fiber; and an optical coupler 70 a) feeding back a part of an output of the DFB fiber laser 40 to the DFB fiber laser 40 via the optical feedback path 50, and b) outputting, to outside, another part of the output of the DFB fiber laser 40, where the optical fiber forming the optical feedback path 50 is longer than a length at which a relaxation oscillation noise in the output to the outside becomes ?110 dB/Hz.

Abstract: A two-beam semiconductor laser device 10 includes: a two-beam semiconductor element LDC having a first and a second semiconductor laser elements LD1 and LD2 that can be driven independently and that are formed integrally on a substrate; and a submount 63 having, mounted on a front part thereof, the two-beam semiconductor laser element LDC with the light-emitting face thereof directed forward and having a first and a second electrode pads 64 and 65 connected to electrodes 61 and 62 of the first and second semiconductor laser element LD1 and LD2 by being kept in contact therewith. The first and second electrode pads 64 and 65 are formed to extend farther behind the two-beam semiconductor laser element LDC, and wires 14 and 16 are wire-bonded behind the two-beam semiconductor laser element LDC.

Abstract: Current may be passed through an n-doped semiconductor region, a recessed metal semiconductor alloy portion, and a p-doped semiconductor region so that the diffusion of majority charge carriers in the doped semiconductor regions transfers heat from or into the semiconductor waveguide through Peltier-Seebeck effect. Further, a temperature control device may be configured to include a metal semiconductor alloy region located in proximity to an optoelectronic device, a first semiconductor region having a p-type doping, and a second semiconductor region having an n-type doping. The temperature of the optoelectronic device may thus be controlled to stabilize the performance of the optoelectronic device.

Abstract: A method and apparatus are disclosed for controlling bandwidth in a multi-portion laser system comprising a first line narrowed oscillator laser system portion providing a line narrowed seed pulse to an amplifier laser system portion, may comprise utilizing a timing difference curve defining a relationship between a first laser system operating parameter other than bandwidth and the timing difference and also a desired point on the curve defining a desired timing difference, wherein each unique operating point on the curve corresponds to a respective bandwidth value; determining an actual offset from the timing difference at the desired point on the curve to an actual operating point on the curve; determining an error between the actual offset and a desired offset corresponding to a desired bandwidth; modifying the firing differential timing to remove the error between the actual offset and the desired offset.

Abstract: The laser device has a gain medium, first and second clads sandwiching the gain medium in the thickness direction, and a cavity structure for resonating the electromagnetic wave generated in the gain medium. The gain medium includes a plurality of active regions for generating an electromagnetic wave and at lease one connecting region sandwiched among the active regions. The first and second clads are each formed of a negative permittivity medium having a permittivity the real part of which is negative relative to the electromagnetic wave. A potential-adjusting portion is arranged between the connecting region and the first clad and between the connecting region and the second clad for adjusting the electric potential of the connecting region.

Abstract: A method of fabricating a color laser, comprising growing a first thin layer of ionic crystal on a substrate. The crystal can comprise many types of ionic crystals, such as sodium chloride or potassium chloride. A second thin layer of a different type of ionic crystal can be deposited above the first ionic crystal layer, such as lithium fluoride or sodium fluoride. An inert metal layer can be deposited between the first and second layers of ionic crystal and above the second layer of ionic crystal. When the first and second ionic crystal layers are radiated with gamma rays, they form color centers at the spots radiated. Because of the difference in crystalline properties of the two different ionic crystal centers, their color centers have different wavelengths. Each of the ionic crystal layers emit light at different characteristic wavelengths when illuminated at their unique absorption frequencies, and can be made to lase separately.

Abstract: A solid-state suspension laser. The novel laser includes a gain medium comprised of a plurality of solid-state gain particles suspended in a fluid. The laser also includes a pump source for pumping the gain particles and a resonator for amplifying and outputting laser light generated by the gain medium. In an illustrative embodiment, the gain medium is adapted to flow, and the pumping of the gain medium occurs outside of the resonator. The flow velocities and the densities of the gain particles in the gain medium can be optimized for optimal absorption efficiency during the pumping and/or for optimal extraction efficiency in the resonator as well as for overall laser performance optimization, including power, efficiency and beam quality scalability.

Abstract: A laser apparatus with all optical-fiber includes a plurality of pumping light sources in different wave bands and an optical-fiber laser system. The optical-fiber laser system includes an optical fiber at least doped with erbium (Er) element and doped with or not doped with ytterbium (Yb) element according to a need. The optical-fiber laser system outputs a laser light through the pumping light source.

Abstract: A laser oscillator for improving efficiency of conversion from solar rays to laser beams is provided. The laser oscillator includes: a laser medium 31 excited by solar rays S to output laser beams; an output mirror 35 having a concave surface 35a opposed to an output end of the laser medium 31; and a light guide 20 having a reflector 22 extending from the output end of the laser medium 31 towards the outside of the laser medium 31 and reflecting the solar rays Sf to guide them to the laser medium 31.

Abstract: According to the present invention, a laser light source comprises plural semiconductor lasers (2), a solid laser (4), a non-linear material (3) as a wavelength conversion element, a reflection coat (5) formed on one facet of the solid laser, and a reflection coat (6) formed on one facet of the non-linear material (3), and the solid laser and the wavelength conversion element are disposed between the both reflection coats to constitute a laser resonator, and plural pump parts (8) in the solid laser (4) which are pumped by the plural semiconductor lasers are separated from each other by 300 ?m or more. Thereby, interference between transverse modes of laser oscillation is avoided, thereby providing a high-power, stable, and compact solid laser light source with which a stable high output power can be obtained.

Abstract: Laser light emission across a wide bandwidth emission spectrum is enabled in a laser device equipped with solid gain media. The laser device is equipped with: a resonator; a plurality of solid gain media, having fluorescent spectra that at least partially overlap with each other, provided within the resonator; and pumping means, for pumping the plurality of solid gain media. The entire fluorescent spectrum width of the plurality of solid gain media is greater than the fluorescent spectrum width of each solid gain medium.

Abstract: Laser light emission across a wide bandwidth emission spectrum is enabled in a laser amplifier equipped with solid gain media. The laser amplifier is equipped with: a resonator; a plurality of solid gain media, having fluorescent spectra that a least partially overlap with each other, provided within the resonator; and pumping means, for pumping the plurality of solid gain media. The entire fluorescent spectrum width of the plurality of solid gain media is greater than the fluorescent spectrum width of each solid gain medium.

Abstract: A laser system comprises first and second laser sub-cavities each including a gain medium arranged to produce volume gain gratings. The laser system further includes a beam combiner arranged to combine emission from each cavity and direct emission from one cavity to the other. As a result a stale, phase-locked coherently combined emission system is provided.

Abstract: The present invention provides an intracavity frequency-converted solid state laser for the visible wavelength region. The laser comprises a semiconductor laser (1) with an extended laser cavity (2). A second laser cavity (4) is formed inside of said extended laser cavity (2). The second laser cavity (4) comprises a gain medium (3) absorbing radiation of the semiconductor laser (1) and emitting radiation at a higher wavelength in the visible wavelength region. The frequency converting gain medium (3) is formed of a rare-earth doped solid state host material. The proposed laser can be manufactured in a highly integrated manner for generating radiation in the visible wavelength region, for example in the green, red or blue wavelength region.

Abstract: The laser device (22) is formed by a stack of laser diodes (4) arranged on plates (6) formed of a material that is electrically conductive and a good heat conductor. In order to obtain a high level of heat evacuation efficiency towards the cooling body (10) and to prevent electric short-circuiting problems, each plate has at the bottom end (24) thereof, an electrically insulating layer deposited on the surface thereof prior to being fixed to the cooling body by a securing material (26) that is preferably a good heat conductor, formed in particular by a braze layer. According to the invention, the insulating layer covers the end face of each plate and also goes up along the lateral faces of the latter over a certain height. The securing material is arranged under the end of the plate and also partially covers the insulating layer along the lateral faces of the plate.

Abstract: A method of avoiding device failure caused by facet heating is described. The method is particularly applicable to a semiconductor laser. In the method, a semiconductor laser facet including GaAsN is hydrogenated such that the bandgap within the facet is greater than the bandgap in the active region of the InGaAsN laser. The increased bandgap reduces absorption of light in the facet and the associated heating that results.

Abstract: A novel method and apparatus for suppressing ASE and parasitic oscillation modes in a high average power laser is introduced. Such an invention, as disclosed herein, uses diffraction gratings to increase gain, stored energy density, and pumping efficiency of solid-state laser gain media, such as, but not limited to rods, disks and slabs. By coupling predetermined gratings to solid-state gain media, such as crystal or ceramic laser gain media, ASE and parasitic oscillation modes can be effectively suppressed.

Abstract: A manufacturing method for manufacturing a laser light source device, includes: providing a first laser element having a first emitter, a second laser element having a second emitter, and a reflection member; adjusting a relative angle between the first laser element and the reflection member; adjusting a relative angle of the second laser element relative to the first laser element by using the reflection member; and adjusting a relative rotation angle between the first laser element and the second laser element and a relative position between the first laser element and the second laser element, so that the light emitted from the first emitter is incident into the second emitter and so that the light emitted from the second emitter is incident into the first emitter.

Abstract: A semiconductor laser diode capable of further improving temperature characteristics while sufficiently preventing a laser beam emission end surface portion from thermal destruction through a window structure is obtained. This semiconductor laser diode comprises an active layer having a window structure on a laser beam emission end surface portion and a p-type layer, formed on the surface of the active layer, containing Mg and Zn as impurities. The impurity concentration of Zn contained in the p-type layer is larger than the impurity concentration of Mg contained in the p-type layer.

Abstract: A laser medium comprises a solid-state host material and dopant species provided within the solid-state host material. A first portion of the dopant species has a first valence state, and a second portion of the dopant species has a second valence state. In an embodiment, a concentration of the first portion of the dopant species decreases radially with increasing distance from a center of the medium, and a concentration of the second portion of the dopant species increases radially with increasing distance from the center of the medium. The laser medium further comprises impurities within the solid-state host material, the impurities converting the first portion of the dopant species having the first valence state into the second portion of dopant species having the second valence state.

Abstract: A color-mixing laser module is disclosed, which is comprised of a laser unit capable of emitting red, blue and green laser beams; a beam combiner, for receiving and converging the laser beams emitted from the laser unit and then directing the converged laser light to illuminate on a light pattern adjusting unit; and the light pattern adjusting unit, capable of receiving the converged laser light from the beam combiner for adjusting the pattern of the same.

Abstract: A measuring arrangement comprises a radiation device (SE), having at least one first surface emitting semiconductor component (1) with a vertical emission direction, a detection device (DE) for detecting reflected radiation, and an evaluation circuit (AS), set up for controlling the radiation device (SE) and the detection device (DE) and for processing a detection result of the detection device (DE). The semiconductor component (1) comprises a semiconductor body (2) with a plurality of active regions (4a, 4b) suitable for generating radiation and arranged at a distance from one another in a vertical direction. In this case, a tunnel junction (5) is monolithically integrated in the semiconductor body (2) between two active regions (4a, 4b) and the two active regions (4a, 4b) are electrically conductively connected by means of the tunnel junction during operation of the semiconductor component (1).

Abstract: Disclosed is a fiber amplifier system including a gain fiber having a single-mode core containing dopant ions capable of producing stimulated emission of light at wavelength ?s when pumped with light of wavelength ?p. Absorbing ion filtering means is operatively associated with the gain fiber to alter the gain curve. If the absorbing ions are the same as the gain ions of the gain fiber, the system further includes means for preventing pump light from exciting the gain ions of the filtering means. The excitation prevention means may take the form of means for attenuating pump light. If the absorbing ions are different from the dopant ions of the gain fiber, such absorbing ions can be subjected to light at wavelength ?p, but they will remain unexcited. Such absorbing ions can be used to co-dope the gain fiber, or they can be incorporated into the core of a fiber that is in series with the gain fiber.