Abstract: An optoelectronic oscillator for generating an optical and/or electric pulse comb, comprising a monolithically integrated passively mode-coupled semiconductor laser and an optical feedback loop which guides a part of the optical radiation of the semiconductor laser and feeds said part back into the semiconductor laser as feedback pulses. Without the influence of the feedback pulses, the semiconductor laser would emit comb-like optical pulses, hereafter referred to as primary pulses, and in the event of an influence, emits comb-like output pulses which have been influenced by the feedback pulses, said output pulses having a lower temporal jitter or less phase noise than the primary pulses. The feedback loop is damped between 27.5 and 37.5 dB, and the time lag of the feedback loop is selected such that each feedback pulse is incident within the temporal half-value width of each subsequent primary pulse.

Abstract: The invention relates to a method of operating a first optical network element (100), particularly an optical network unit, ONU, wherein said method comprises the following steps: performing a coarse tuning process (2100) of at least one transmission wavelength which is used by said first optical network element (100) for transmitting an optical signal to a second optical network element (200), particularly an optical line terminal, OLT, and performing a fine tuning process (2200) of said at least one transmission wavelength, wherein said fine tuning process (2200) is preferably performed after said coarse tuning process (2100).

Abstract: An apparatus for generating a pulse train with an adjustable time interval is provided. The apparatus, being an annular optical cavity structure, includes a seed source receiving end, a pump source receiving end, an optical coupler, an optical combiner, a gain fiber, an optical path time regulator and a beam splitter. Thus, the apparatus is capable of generating a pulse train with an adjustable time interval to increase material processing quality and speed.

Abstract: Swept source designs that eliminate or significantly reduce artifacts in optical coherence tomography are presented. One embodiment of the present invention is a source design that frequency shifts the coherence revival interference signal to a frequency larger than the A/D detection bandwidth or the post-processing bandwidth. In another embodiment, the introduced frequency shift is large enough to introduce a Doppler shift of the modes of the laser, which causes a blurring of the comb function, and thus eliminates or reduces mode hopping. In another embodiment, adjusting the cavity optical path length prior to data acquisition depending on the given optical layout configuration to reduce or eliminate coherence revival artifacts is described.

Abstract: A laser anti-reflection device includes a polarizing beam splitter, a ?/4 wave plate and an absorber disposed in an outgoing light path of a laser emitting linearly polarized light with a wavelength of ?. The linearly polarized light from the laser passes through the polarizing beam splitter and the ?/4 wave plate in turn to become a circularly polarized light beam. Part of the circularly polarized light beam is then reflected by a workpiece to be processed along the original light path and passes the ?/4 wave plate to become a linearly polarized light beam with a polarization direction vertical to that of the outgoing linearly polarized light beam. The vertical polarized beam passes the polarizing beam splitter, deviates from the light path of the outgoing linearly polarized light beam and reaches the absorber. The laser anti-reflection device prevents reflected light from damaging the laser from high power lasers.

Abstract: Embodiments of the invention describe integrating a phase shifting component into a cavity of a laser. Said phase shifter is capable of a continuous phase shift at a single wavelength over a large range (where the maximum energy consumption of the phase shifting component does not scale with the phase shifting range). In other words, said phase shifter is used to form a configurable optical cavity length for a laser. Embodiments of the invention thus utilize a plurality of optical cavity lengths—including one or more optical cavity lengths to potentially shift the phase of the output optical signal, to maintain a laser cavity's output wavelength and avoid spatial mode-hops in the presence of fluctuations such as temperature drift or changes to the drive current of the laser.

Abstract: An optical parametric oscillator comprising: an optical cavity; a semiconductor gain-medium located within the optical cavity, such that together they form a semiconductor laser, and a nonlinear material located within the cavity such that the nonlinear material continuously generates down-converted idler- and signal-waves in response to a pump-wave continuously generated by the semiconductor gain-medium, wherein the pump wave is resonant within the optical cavity and one or other but not both of the down-converted waves is resonant within the pump wave cavity or a further optical cavity. Brewster plates ensure singly resonant optical parametric oscillators and a birefringent filer is used for frequency setting. Coupled cavities allow for setting the photon lifetime in the cavity that relaxation oscillations are prevented.

Abstract: An Integrated Laser Field Conjugation System (ILFCS) for end-to-end compensation of high-energy laser for propagation through turbulence with non-cooperative target. ILFCS using interferometric slaving technique and stand-alone adaptive optical systems to effect pre-compensation of amplitude and phase aberrations in turbulent medium, providing pre-compensation for aberrations in a laser amplifier. Performing compensation functions in low-power beam paths, increasing capability, reducing cost, reducing size compensation components for phase correction devices. Pre-compensating low-power master oscillator beam for aberrations in both high-power amplifier and turbulent propagation path-to-target with configuration enabling wavefront sensing of aberrations. Can be configured to perform phase compensation, or compensation of phase/amplitude aberrations. Capability to compensate aberrations in master oscillator beam.

Abstract: A master oscillator system may include a grating configured to function as one resonator mirror in an optical resonator, a spectral bandwidth tuning unit configured to tune the spectral bandwidth of a laser beam transmitted within the optical resonator, a storage unit configured to store a control value of the spectral bandwidth tuning unit corresponding to a desired spectral bandwidth and a controller configured to control the spectral bandwidth tuning unit based on the control value stored in the storage unit.

Abstract: A method for fabricating an optical device including: a first step of preparing a carrier having a first area and a second area, both edges of the second area having a wall of a step, one edge of the second area being adjacent to the first area, the first area having a first thickness, the second area having a second thickness larger than the first thickness, a second step of mounting the carrier on a temperature control device after the first step, and a third step of mounting a first optical component on the first area of the carrier after the second step.

Abstract: A laser apparatus includes an external cavity laser (ECL) where the optical signal is modulated by an electrical modulation signal for modulating in frequency the laser output signal. The modulation in frequency produces a modulation of intensity (power) of the laser output signal, also denoted amplitude modulation (AM). A method of controlling the AM amplitude of a signal emitted by an ECL includes a gain medium, a phase element with variable transmissivity induced by the modulation, and a spectrally selective optical filter that selects and keeps the AM amplitude below a certain desired value or minimizes such value. A control method and a laser apparatus are also described in which the reduction of the AM component of the output power is achieved by acting on the gain of the gain medium of the ECL.

Abstract: Embodiments of an ultra-stable frequency reference generating system and methods for generating an ultra-stable frequency reference using a two-photon Rubidium transition are generally described herein. In some embodiments, a cavity-stabilized reference laser comprising a laser source is locked to a stabilized cavity. A Rubidium cell is interrogated by a stabilized laser output to cause at least a two-photon Rubidium transition and a detector may detect fluorescence resulting from spontaneous decay of the upper state Rubidium transition. The output of the detector is provided at a wavelength of the fluorescence to lock the cavity-stabilized reference laser to generate a stabilized laser output. A frequency comb stabilizer may be locked to the stabilized laser output to generate a super-continuum of optical wavelengths for use in generating an ultra-stable frequency reference.

Abstract: An external-cavity tuneable laser includes a gain medium and a tuneable mirror wherein at least the tuneable mirror is in thermal contact with a thermally conductive platform. The tuneable mirror lays substantially horizontally on the thermally conductive platform significantly improving the thermal contact of the tuneable mirror with the platform. A laser beam from the gain medium is directed onto the tuneable mirror, which is mounted substantially horizontally with respect to the thermally conductive platform, by means of a deflector that deflects the beam or a large part of it toward one of the principal surfaces of the tuneable mirror. The resulting laser cavity is a folded cavity. The thermally conductive platform is preferably thermally coupled to a TEC that provides thermal control for the platform. The deflector may be a beam splitter that deflects part of the incoming light and transmits the remaining part.

Abstract: An optical device including: a carrier having a first area and a second area, both edges of the second area having a wall of a step, one edge of the second area being adjacent to the first area, the first area having a first thickness, the second area having a second thickness larger than the first thickness; and a first optical component mounted on the first area of the carrier, the second area of the carrier being an absence area of a component.

Abstract: A wavelength-tunable directly modulated fiber ring laser is provided. Generally speaking, the wavelength-tunable directly modulated fiber ring laser employs an RSOA (reflective semiconductor optical amplifier) and an OTF (optical tunable filter) to construct a novel ring resonant cavity. Additionally, a signal generator can be further employed to transmit modulated signals to the RSOA, whereby generating light wave with the modulated signals, so as to provide tunable wave-length and direct modulation at the same time.

Abstract: A repetition frequency control device includes a slave photoelectric conversion unit which converts a slave laser light pulse into a slave electrical signal, a master photoelectric conversion unit which converts a master laser light pulse into a master electrical signal, a frequency change unit which changes the repetition frequency of the master electric signal by a predetermined value, a phase comparator which detects a phase difference between the slave electric signal and the output from the frequency change unit, and a loop filter which removes a high frequency component of an output from the phase comparator, where the repetition frequency of the master laser does not undergo control based on one or both of the master electric signal and the slave electric signal.

Abstract: A method and apparatus is disclosed for operating a laser output light beam pulse line narrowing mechanism that may comprise a nominal center wavelength and bandwidth selection optic; a static wavefront compensation mechanism shaping the curvature of the selection optic; an active wavefront compensation mechanism shaping the curvature of the selection optic and operating independently of the static wavefront compensation mechanism. The method and apparatus may comprise the nominal center wavelength and bandwidth selection optic comprises a grating; the static wavefront compensation mechanism applies a pre-selected bending moment to the grating; the active wavefront compensation mechanism applies a separate selected bending moment to the grating responsive to the control of a bending moment controller based on bandwidth feedback from a bandwidth monitor monitoring the bandwidth of the laser output light beam pulses. The active wavefront compensation mechanism may comprise a pneumatic drive mechanism.

Abstract: A laser system for effective injection seeding is configured with a master oscillator lasing a narrowband seed radiation which is characterized by a single longitudinal master mode injected into a slave oscillator so that the latter generates a broadband slave radiation with a dominant slave mode and side slave modes. The slave radiation is coupled into an input of a SM fiber laser amplifier operative to output an amplified radiation with the spectra which is substantially as narrow as the spectra of the slave radiation.

Abstract: In order to improve a solid-state laser, in particular a solid-state disc laser, comprising a resonator (40) that defines a resonator radiation field (30) and at least one solid-state disc (12) with the resonator radiation field (30) passing through it, in such a manner that the thermal lens effect can be at least substantially compensated, it is proposed that in reflection the resonator radiation field (30) strikes at least one first adaptive mirror unit (50, 70), with which a distortion of the resonator radiation field (30) as a result of a thermal lens effect of the at least one solid-state disc (12) can be substantially compensated. An adaptive mirror unit (50) can be configured by a heated (58a, 58b) glass sheet (54) with an HR layer (52), for example, or by a pressure-induced deformation by means a fluid (78) in a space (76), which is enclosed with the mirror (72, 74).

Abstract: One example disclosed herein relates to a method of at least partially optimizing one or more output performance parameters of a laser die. The method includes an act of identifying one or more output performance parameters to be at least partially optimized, an act of identifying one or more design parameters associated with the one or more output performance parameters, an act of determining a subset of the one or more design parameters that should be varied so as to at least partially effect the one or more output performance parameters, an act of varying the subset of design parameters to produce one or more intermediate results, and an act of using the intermediate results to determine values for the one or more design parameters such that the one or more performance parameters are at least partially optimized.

Abstract: A method of controlling a frequency-converted laser source is provided where the laser source comprises a laser cavity, an external optical feedback component, a wavelength selective component, and a wavelength conversion device and the method comprises driving a gain section of the laser cavity with a gain signal that comprises a data component and a modulation component. The modulation component of the gain signal comprises a gain modulation amplitude IMOD that is sufficient to shift the available cavity modes in the spectral domain such that lasing at several different cavity modes sequentially is established as the gain signal is modulated.

Abstract: A dual-cavity single longitudinal mode (SLM) laser oscillator generates a pulsed laser signal having a long pulsewidth, long coherence length, and good shot-to-shot energy stability. The laser oscillator has a first cavity between an output coupler and a rear mirror and a second cavity between the output coupler and an intra-cavity mirror disposed between the output coupler and rear mirror. High-loss cavity optics and a passive Q-switch achieve a very high number of round trips that reduce the number of cavity modes down to two or three. The dual cavity design further discriminates between the remaining modes and allows SLM operation. The laser oscillator and an amplifier can be used as a pump laser for a laser system that generates red, green, and blue pulses for holographic recording. A wavelength conversion stage uses optical parametric amplifier(s), doubling crystals, and sum-frequency mixers to produce RGB light from the pump pulses.

Abstract: In order to improve a solid-state laser, in particular a solid-state disc laser, comprising a resonator (40) that defines a resonator radiation field (30) and at least one solid-state disc (12) with the resonator radiation field (30) passing through it, in such a manner that the thermal lens effect can be at least substantially compensated, it is proposed that in reflection the resonator radiation field (30) strikes at least one first adaptive mirror unit (50, 70), with which a distortion of the resonator radiation field (30) as a result of a thermal lens effect of the at least one solid-state disc (12) can be substantially compensated. An adaptive mirror unit (50) can be configured by a heated (58a, 58b) glass sheet (54) with an HR layer (52), for example, or by a pressure-induced deformation by means a fluid (78) in a space (76), which is enclosed with the mirror (72, 74).

Abstract: An apparatus comprising a laser source configured to emit a light beam along a first path, an optical beam steering component configured to steer the light beam from the first path to a second path at an angle to the first path, and a diffraction grating configured to reflect back at least a portion of the light beam along the second path, wherein the angle determines an external cavity length. Included is an apparatus comprising a laser source configured to emit a light beam along a first path, a beam steering component configured to redirect the light beam to a second path at an angle to the first path, wherein the optical beam steering component is configured to change the angle at a rate of at least about one Kilohertz, and a diffraction grating configured to reflect back at least a portion of the light beam along the second path.

Abstract: The introduction of a magnetic electron beam orbit chicane between the wiggler and the downstream initial bending dipole in an energy recovering Linac alleviates the effects of radiation propagated from the downstream bending dipole that tend to distort the proximate downstream mirror of the optical cavity resonator.

Abstract: This invention relates to a wavelength tunable light source, comprising a main resonator, having a first and a second mirrored end, defining an effective cavity length, i.e. an optical beam path length of a resonant mode of the cavity, an optical gain element, having a first and a second opposing end surface, said second surface being positioned within said main resonator, a mirror element constituting said second mirrored end, and a dispersive focusing resonator element, being positioned along a beam path between said second end surface and said mirror element, whereby said effective cavity length of said main resonator is arranged to be varied.

Abstract: The hologram recording technology expected to realize ultrahigh-density information recording is one of the post Blu-ray Disc technology. When we think about developing a drive based on this technology and suitable for consumer electronics, it is considered most desirable from the viewpoint of upward compatibility to solve the problem of the BD-compatibility. The problem in sharing the laser light source between the hologram recording device and the current optical disc device, however, is that the hologram recording requires a high-coherent, single-mode light beam, while the current optical discs requires a low-coherent, multi-mode light beam. In point of the coherence of the light source, the above two cases require the light beams of the characteristics opposite to each other, and this presents an important task.

Abstract: An RF cavity is provided with a plurality of tubes that are formed into a tubular cage in a predefined shape to define the RF cavity. A selected number of tubes and a selected tube diameter are provided to form a confinement cage for the RF fields within the RF cavity defined by the tubes. The multiple, small metal tubes are selectively bent to form different cavity shapes and sizes as needed to accelerate the particles and function as a confinement cage for the RF fields within the RF cavity defined by the tubes. The cost to fabricate RF cavities using the tubular cage design is significantly lower than the cost of producing a solid cavity using conventional fabrication technology.

Abstract: A laser diode device capable of obtaining high light efficiency and improving output by using an AlGaInN compound semiconductor as a material is provided. The laser diode device includes semiconductor layer which has an active layer and is made of a nitride Group III-V compound semiconductor containing at least one of aluminum (Al), gallium (Ga), and indium (In) among Group 3B elements and nitrogen (N) among Group 5B elements. The active layer has a strip-shaped light emitting region whose width W is from 5 ?m to 30 ?m, length L is from 300 ?m to 800 ?m, and output of laser light from the active layer is 200 mW or more.

Abstract: A structured sub-mount assembly is disclosed to support a hybrid assembly of tunable filters. The sub-mount assembly is constructed to provide a high thermal resistance path and high mechanical resonance frequency. Optionally, the structured sub-mount assembly includes a temperature-controlled phase adjust component disposed approximately midway between the two tunable filters. The structured sub-mount assembly may be part of a tunable laser or other application.

Abstract: A reflection element 3 disposed in an optical waveguide element 2 returns a part of light to a semiconductor laser diode element 1 so that the semiconductor laser diode element 1 oscillates in a coherent collapse mode, and a semiconductor light amplifier 7 is optically coupled to the optical waveguide element 2, and amplifies an optical output from optical waveguide element 2, so as to provide a high-power fundamental-wave light source.

Abstract: Apparatus, systems, and methods are provided that utilize a material inserted into a laser cavity such that the material has an optical length that varies as the laser cavity varies to keep the repetition rate constant. The material may provide auto-stabilization of the optical output form the laser cavity.

Abstract: This invention relates to the stabilization of a laser source used in opto-electronics, specifically a source comprising a semiconductor laser diode. Such laser sources are often used as so-called pump lasers for fiber amplifiers in the field of optical communication, erbium-doped fiber amplifiers being a prominent example. Such lasers are usually designed to provide a narrow-bandwidth optical radiation with a stable power output in a given frequency band. The present invention now concerns such a laser source using external reflector means, preferably consisting of one or more appropriately designed fiber Bragg gratings, providing very high relative feedback with an extremely narrow bandwidth, combined with a very long external cavity encompassing about 100 modes or more and an extremely low front facet reflectivity of the laser diode. Also, the FWHM bandwidth of the external reflector is selected to be significantly smaller than the distance between the modes within the laser diode.

Abstract: A laser arrangement is provided, in which a Lyot filter arrangement is operative to effect single mode operation. The birefringent element of the Lyot filter arrangement has a cavity folding mirror on one side thereof and a polarizing element on another side thereof, such that the free spectral range of the Lyot filter is improved. Preferably, the Lyot filter arrangement and the laser gain material are located in different branches of the folded cavity.

Abstract: A light emitting device is disclosed that emits light from the surface in a broad spectral range and in a broad range of angles tilted with respect to the direction normal to the exit surface. An apparatus for generating wavelength-stabilized light is formed of a light-emitting device, an external cavity and at least one external mirror. Light emitted by the light-emitting device at a certain preselected angle, propagates through the external cavity, impinges on the external mirror and is reflected back. Light emitted at other angles does not impinge on the external mirror. Thus, a feedback occurs only for the light emitted at a preselected angle. Light impinged on the external mirror and reflected back undergoes interference with the emitted light. The interference can be constructive or destructive. Constructive interference results in a positive feedback. The positive feedback occurs, if light emitted by the light-emitting device is reflected back and reaches the active region in phase, i.e.

Abstract: A pulsed laser is disclosed comprising an active lasing medium (1), an output coupler (5) and a rear cavity mirror (6). The rear cavity mirror (6) is attached to a mount (21) via an intermediate attachment (15). Heating elements are embedded within the attachment (15). The attachment (15) is heated in order to vary the physical length of the laser cavity in a manner which seeks to stabilise the output energy and wavelength of the laser pulses emitted from the laser cavity.

Abstract: A laser system for a spectroscopic catheter system uses multiple semiconductor gain media having gain peaks at different wavelengths. The output from the gain media is preferably coupled into single-mode fiber using conventional opto-electronic packaging techniques. As a result, the laser oscillator source has a spectral output that is wider than the gain bandwidth of a single medium to enable it to access the entire spectrum of interest, which is presently in the near infrared. Moreover, the semiconductor gain media can be packaged in a stable and controlled environment for long-term performance.

Abstract: An apparatus is described that includes an optical storage cavity comprising a planar mirror and a spherically curved mirror that form an optical path therebetween. A pump laser introduces optical pulses into the cavity. A folding mirror is disposed in the optical path between the planar mirror and the spherically curved mirror such that a beam waist is formed between the folding mirror and the second spherically curved mirror. The optical pulses preferably interact with selected particles disposed in the optical path at the waist. The apparatus further comprises a first transducer which adjusts the distance between the spherical mirror and the folding mirror to change a characteristic of the beam waist. A second transducer adjusts the distance between the planar mirror and the spherical mirror to change the optical path length of the cavity. The optical cavity is arranged such that the change in path length due to the second transducer does not significantly affect the characteristic of the beam waist.

Abstract: In an optical signal transmission system which can perform high-speed optical transmission not lower than 1 Gbps, VCSEL has light-emission points. A core diameter of an optical fiber GI-POF is set to not lower than 200 ?m, and the light-emission points of VCSEL are arranged inside an outer periphery at an end face of GI-POF. A polymerization composition material constituting the core of GI-POF is made of a compound containing deuterated poly methacrylic ester. A wavelength of the light beam of VCSEL is set to the range of 770 nm to 810 nm.

Abstract: A laser apparatus in a hermetically sealed container and methods for hermetically sealing the laser. The laser apparatus comprising an external cavity laser and a modulator in a single hermetically sealed enclosure.

Abstract: Apparatus, systems, and methods are provided that utilize a material inserted into a laser cavity such the material has an optical length that varies as the laser cavity varies to keep the repetition rate constant. The material may provide auto-stabilization of the optical output form the laser cavity.

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

Abstract: Alignment of a laser apparatus is achieved by actively aligning components of the laser apparatus and then passively deriving an optical axis from that alignment. This passive derivation can be achieved by identifying features of an actively aligned optical element, deriving positional data for those features, and developing an optical axis from that positional data. The derivation of positional data may be performed over a particular coordinate system of an image taken of the feature, e.g., obtained by a vision system. The positional data and optical axis may be extrapolated out to a reference coordinate system for use in passively aligning other optical elements.

Abstract: In a display device that displays a video by scanning coherent light across a screen, modulation at high speeds and gradation are necessary for a coherent light source. An oscillation wavelength of a semiconductor laser outputting the fundamental wave is changed at high speeds through the plasma effect induced by applying a pulse current to the coherent light source. A change of the wavelength causes the output of a higher harmonic generated in a light wavelength conversion element to change, and gradation is produced using such a change.

Abstract: Optical switches and logic devices comprising microstructure-doped nanocavity lasers are described. These switches and logic devices have gain and thus can be cascaded and integrated in a network or system such as for example on a chip. Exemplary switching elements switch the intensity, wavelength, or direction of the output. Exemplary logic devices include AND, OR, NAND, NOR, NOT, and XOR gates as well as flip-flops. Microfluidic sorting and delivery as well as optical tweezing and trapping may be employ to select and position a light emitter in an nanooptical cavity to form the nanolaser.

Abstract: A semiconductor optoelectronic device includes at least one cavity and one multilayered interference reflector. The cavity is designed preferably to possess properties of an antiwaveguiding cavity, where no optical modes propagate in the lateral plane. The existing optical modes are the modes propagating in the vertical direction or in a direction tilted to the vertical direction at an angle smaller than the angle of the total internal reflection at the semiconductor/air interface. This design reduces the influence of parasitic optical modes and improves characteristics of optoelectronic devices including vertical cavity surface emitting lasers, tilted cavity lasers emitting through the top surface or the substrate, vertical or tilted cavity resonant photodetectors, vertical or tilted cavity resonant optical amplifiers, and light-emitting diodes.

Abstract: A CO2 laser reference oscillator (RO) can provide injection seeding to a Q-switched (QS) or Q-switched cavity dumped (QSCD) CO2 laser, where the output frequency of the RO laser is locked to the peak of the laser line by the use of appropriate electronics to dither one of the resonator mirrors of the reference oscillator. This injected radiation seeds the radiation building up within the Q-switched laser cavity, such that the oscillating frequency favors the wavelength of the injected radiation. An electronic feedback control circuit can be used to lock an axial mode of the Q-switched laser to line center. The change in build-up time of the pulses within the QS laser can be used to maintain cavity length at a value that enables oscillating at the peak of the same laser line that is injected into QS laser.

Abstract: A wavelength-locking arrangement for a diode-laser bar includes a cylindrical fast-axis collimating lens and a fast-axis corner reflector. An optical filter is located between the cylindrical lens and the corner reflector for defining the locked wavelength. The corner reflector provides that radiation emitted by each of the diode-lasers and collimated by the cylindrical lens is reflected back to the cylindrical lens and is focused by the cylindrical lens back into the diode-laser from which the radiation was emitted, independent of the fast-axis alignment of the diode-laser with the cylindrical lens.

Abstract: The present invention is a self-seeded laser diode. The laser diode obtains a gain by itself without using expansive erbium-doped fiber amplifiers. Hence, the cost is reduced and the system is simplified.

Abstract: This invention consists of an optical external cavity having specialized Brewster angle wedges. The external cavity apparatus utilizes several types of very high index of refraction wedges made from semiconductor and special glass materials. The apparatus limits the oscillation of the optical wavelength modes emitted by a diode laser. In addition, such cavities also simplify the motions of the moveable mirror that returns these selected laser photons to the cavity input beam path or fiber. The wedge also disperses the laser light to isolate the desired wavelength band better than the currently used grating systems. Wavelengths other than the desired wavelength band are dispersed, then reflected at angle away from the return fiber and thus not returned to the amplification cavity inside the laser. The apparatus then emits only the laser photon mode desired by the user.