Abstract: Feedback loops can be used to shift and stabilize the carrier-envelope phase of a frequency comb from a mode-locked fibers laser or other optical source. Compared to other frequency shifting and stabilization techniques, feedback-based techniques provide a wideband closed-loop servo bandwidth without optical filtering, beam pointing errors, or group velocity dispersion. It also enables phase locking to a stable reference, such as a Ti:Sapphire laser, continuous-wave microwave or optical source, or self-referencing interferometer, e.g., to within 200 mrad rms from DC to 5 MHz. In addition, stabilized frequency combs can be coherently combined with other stable signals, including other stabilized frequency combs, to synthesize optical pulse trains with pulse durations of as little as a single optical cycle. Such a coherent combination can be achieved via orthogonal control, using balanced optical cross-correlation for timing stabilization and balanced homodyne detection for phase stabilization.

Abstract: Apparatus and methods for anisotropic pumping of a Kerr lens modelocked laser. Direct diode laser pumping of an ultrafast Kerr lens modelocked laser oscillator is accomplished. Diode lasers generate severely anisotropic beams, meaning the pump beam has a higher-beam-quality dimension and a lower-beam-quality dimension. By spatially overlap of the pump beam higher-beam-quality dimension and the KLM laser mode, KLM operation is accomplished. Multiple laser diode pump beams are combined in counterpropagating and same-side configurations.

Abstract: To provide a passive Q-switch-type solid laser apparatus for outputting a high peak-power pulse laser whose pulse energy is large and pulse-time width is small. A passive Q-switch-type solid laser apparatus has: two reflection elements for forming an oscillator; a solid gain medium being disposed between the two reflection elements; a saturable absorber being disposed between the two reflection elements; an excitation device for exciting the solid gain medium; and a cross section control device for making at least one of a stimulated emission cross section of the solid gain medium and an absorption cross section of the saturable absorber closer to another one of them; and the cross section control device is equipped with at least one or both of a temperature control device for retaining the solid gain medium at a predetermined temperature and an oscillatory-wavelength control device for fixating an oscillatory wavelength at a predetermined wavelength.

Abstract: Coherent and compact supercontinuum light sources for the mid IR spectral regime are disclosed and exemplary applications thereof. The supercontinuum generation is based on the use of highly nonlinear fibers or waveguides. In at least one embodiment the coherence of the supercontinuum sources is increased using low noise mode locked short pulse sources. Compact supercontinuum light sources can be constructed with the use of passively mode locked fiber or diode lasers. Wavelength tunable sources can be constructed using appropriate optical filters or frequency conversion sections. Highly coherent supercontinuum sources further facilitate coherent detection schemes and can improve the signal/noise ratio in lock in detection schemes.

Abstract: The laser system may include: a clock generator; a mode-locked laser device having an optical resonator; a controlling device capable of controlling resonator length of the optical resonator; a detector disposed in an optical path of the pulse laser beam, configured to detect the pulse laser beam and output a detection signal; a switching device disposed in the optical path of the pulse laser beam, capable of switching the pulse laser beam; and a controller, capable of controlling the controlling device based on the clock signal outputted by the clock generator and on the detection signal outputted by the detector, and capable of controlling the switching device based on the clock signal outputted by the clock generator and on a timing signal outputted by an external device.

Abstract: A method for quasi-synchronous tuning of wavelength or frequency of grating external-cavity semiconductor laser and a corresponding semiconductor laser are provided. A grating or mirror is rotated around a quasi-synchronous tuning point (Pq) as rotation center, so as to achieve the frequency selections by grating and resonance cavity in quasi-synchronous tuning, wherein the angle of the line between the quasi-synchronous tuning point (Pq) and a conventional synchronous tuning point (P0) with respect to the direction of light incident on the grating is determined according to the angle difference between the incidence angle and diffraction angle of light on the grating. According to present invention, approximately synchronous tuning of laser is achieved with a simple and flexible design.

Abstract: In one embodiment, the invention relates to systems, methods and devices for improving the operation of an electromagnetic radiation source or component thereof. In one embodiment, the source is a laser source. A Fourier domain mode locked laser can be used in various embodiments. The sources described herein can be used in an optical coherence tomography (OCT) system such as a frequency domain OCT system. In one embodiment, laser coherence length is increased by compensating for dispersion. A frequency shifter can also be used in one embodiment to compensate for a tunable filter induced Doppler shift.

Abstract: Normal group velocity dispersion mode-locked optical frequency combs are provided on-chip. On-chip coherent frequency comb generation includes pulses showing temporal durations of about 74 fs. Pump detuning and bandpass filtering are provided for stabilizing and shaping the pulses from normal group velocity dispersion microresonators.

Abstract: There is provided a light source including a mode-lock laser unit that includes a semiconductor laser and an external resonator unit and emits a laser beam having a predetermined frequency, the semiconductor laser including a saturable absorber unit that applies a reverse bias voltage and a gain unit that applies a gain current, a semiconductor optical amplifier that performs amplification modulation on the laser beam emitted from the mode-lock laser unit, a laser clock generating unit that generates a laser clock synchronized with the laser beam based on a signal detected from the saturable absorber unit when the laser beam oscillates in the mode-lock laser unit, and a modulating unit that generates a driving current synchronized with the laser clock and applies the driving current to the semiconductor optical amplifier.

Abstract: A MEMS-based swept laser source is formed from two coupled cavities. The first cavity includes a first mirror and a fully reflective moveable minor and operates to tune the output wavelength of the laser. The second cavity is optically coupled to the first cavity and includes an active gain medium, the first mirror and a second mirror. The second cavity further has a length substantially greater than the first cavity such that there are multiple longitudinal modes of the second cavity within a transmission bandwidth of the first cavity output.

Abstract: Apparatus, systems, and methods of generating multi combs can be used in a variety of applications. In various embodiments, an etalon can be disposed in the laser cavity of a mode-locked laser to adjust frequency combs. Additional apparatus, systems, and methods are disclosed.

Abstract: This mode-locked laser light source device comprises a semiconductor optical amplifier wherein carriers are generated by the injection of an injection current thereinto, a pulse of laser light is amplified by the consumption of the carriers, and phase modulation equivalent to self-phase modulation depending on the pulse intensity of the laser light occurs due to a change in the density carriers; a sweep modulation unit which the oscillation wavelength of the pulse of the laser light emitted from the semiconductor optical amplifier is variable; a resonator which returns the pulse of the laser light modulated by the sweep modulation unit to the semiconductor optical amplifier to cause a laser oscillation phenomenon; and a dispersion compensator which is used in an anomalous dispersion region and changes the return time of the pulse of the laser light depending on the wavelength of the pulse of laser light guided in the resonator.

Abstract: A control system for improving and stabilizing Fourier domain mode locking (FDML) operation. The control system may also provide regulation of FDML operational parameters such as filter tuning, laser gain, polarization, polarization chromaticity, elliptical polarization retardance, and/or dispersion. The control system may be located internal to or external from the FDML laser cavity.

Abstract: A semiconductor-laser-device assembly includes a mode-locked semiconductor-laser-element assembly including a mode-locked semiconductor laser element, and a dispersion compensation optical system, on which laser light emitted from the mode-locked semiconductor laser element is incident and from which the laser light is emitted; and a semiconductor optical amplifier having a layered structure body including a group III-V nitride-based semiconductor layer, the semiconductor optical amplifier configured to amplify the laser light emitted from the mode-locked semiconductor-laser-element assembly.

Abstract: Embodiments of the present invention generally relate to high energy, ultrashort pulses from a net normal dispersion ytterbium fiber laser with an anomalous dispersion higher-order mode fiber. More specifically, embodiments of the present invention relate to a fiber oscillator with all-fiber dispersion compensation delivering pulse parameters comparable to solid-state oscillators having good compensation of higher order dispersion and intracavity nonlinearities. In one embodiment of the present invention, an oscillator comprises a length of single mode fiber and a length of higher-order mode fiber, where the group delay dispersion (GDD) of the higher-order mode fiber is chosen to match 50% or more of the GDD of the single mode fiber; wherein a third-order dispersion of the oscillator matches a nonlinear phase buildup in a cavity of the oscillator, and the nonlinear phase buildup is dependent upon the pulse energy of the oscillator.

Abstract: Provided is an alignment method of a semiconductor optical amplifier with which optimization of coupling efficiency between incident laser light and light waveguide of the semiconductor optical amplifier is enabled without depending on an external monitoring device. The alignment method of a semiconductor optical amplifier is a method that optically amplifies laser light from a laser light source and outputs the optically amplified laser light, which adjusts relative position of the semiconductor optical amplifier with respect to the laser light entering into the semiconductor optical amplifier by flowing a given value of current to the semiconductor optical amplifier while entering the laser light from the laser light source to the semiconductor optical amplifier so that a voltage applied to the semiconductor optical amplifier becomes the maximum.

Abstract: Methods, systems and apparatus are disclosed for delivery of pulsed treatment radiation by employing a pump radiation source generating picosecond pulses at a first wavelength, and a frequency-shifting resonator having a lasing medium and resonant cavity configured to receive the picosecond pulses from the pump source at the first wavelength and to emit radiation at a second wavelength in response thereto, wherein the resonant cavity of the frequency-shifting resonator has a round trip time shorter than the duration of the picosecond pulses generated by the pump radiation source. Methods, systems and apparatus are also disclosed for providing beam uniformity and a sub-harmonic resonator.

Abstract: A system and method for efficiently laser marking a polymer target material, and more particularly a transparent polymer target material, is presented. The system includes a visually transparent polymer target material comprising a surface and a near 2 ?m fiber laser, the fiber laser having a peak power equal to or greater than 10 kW, a pulse repetition rate equal to or greater than 1 kHz, and an average power equal to or less than 20 W. In certain embodiments, the fiber laser may be a Q-switched fiber laser having a pulse width equal to or less than 200 ns or a mode-locked fiber laser having a pulse width equal to or less than 100 ps. The method includes producing, using the fiber laser, a mark that is not transparent to visible wavelengths on the surface of the polymer target material without damaging it.

Abstract: An Environmentally stable optical fiber mode-locked laser generating device having an achromatic quarter wave plate is disclosed. An optical fiber unit is formed of a polarization maintaining (PM) optical fiber, and a Bragg grating is formed on a first region from one end in direction to the other end, a gain material is doped on a core of a remaining second region. An optical coupling unit provides a pump laser input to one end of the optical fiber unit, and outputs a laser input from the optical fiber unit. A lens unit converts a laser output from the other end of the optical fiber unit and focuses the laser on a certain regime.

Abstract: A laser apparatus and bio-imaging apparatus are provided, which include: a mode-lock laser unit including a saturable absorber section that applies a bias voltage, a gain section that feeds a gain current, a semiconductor laser that emits laser light, and an external resonator; an optical modulation unit performing amplification modulation on the laser light emitted from the mode-lock laser unit; a reference signal generation unit generating a master clock signal and supplying a signal synchronized with the master clock signal to the gain section of the semiconductor laser; and a driving circuit generating a driving pulse used to drive the optical modulation unit based on the reference signal.

Abstract: A fiber laser having a ring resonance path comprises a pump light source, a Yb-doped optical fiber and a light modulation unit. The pump light source emits a pump light. The Yb-doped optical fiber is coupled with the pump light. The light modulation unit includes a grating pair, a diaphragm and two reflective elements. The grating pair is coupled with the pump light. The diaphragm includes an aperture. The light transmitted by the grating pair partially passes through the aperture and reaches one of the reflective elements to become a reflective light, and the reflective light passes through the aperture and is transmitted through the grating pair and the other reflective element to be coupled back with the ring resonance path.

Abstract: There is disclosed a femtosecond laser apparatus including a first laser material comprising Ng, Np and Nm axes spatially perpendicular to each other; a second laser material comprising Np axis, Nm axis and Ng axis; and a first laser diode and second laser diodes, wherein the traveling direction of laser beams generated from the first and second laser materials is substantially parallel to Ng axis of the first laser material and the polarizing direction of laser beams generated from the first and second laser materials is substantially parallel to Np axis of the first laser material, and the traveling direction of laser beams generated from the first and second laser materials is substantially parallel to Np axis of the second material and the polarizing direction of laser beams generated from the first and second laser materials is substantially parallel to Nm axis of the second laser material.

Abstract: In the conventional contaminant particle/defect inspection method, if the illuminance of the illumination beam is held at not more than a predetermined upper limit value not to give thermal damage to the sample, the detection sensitivity and the inspection speed being in the tradeoff relation with each other, it is very difficult to improve one of the detection sensitivity and the inspection speed without sacrificing the other or improve both at the same time. The invention provides an improved optical inspection method and an improved optical inspection apparatus, in which a pulse laser is used as a light source, and a laser beam flux is split into a plurality of laser beam fluxes which are given different time delay to form a plurality of illumination spots. The scattered light signal from each illumination spot is isolated and detected by using a light emission start timing signal for each illumination spot.

Abstract: Compact optical frequency sources are described. The comb source may include an intra-cavity optical element having a multi-material integrated structure with an electrically controllable active region. The active region may comprise a thin film. By way of example, the thin film and an insulating dielectric material disposed between two electrodes can provide for rapid loss modulation. In some embodiments the thin film may comprise graphene. In various embodiments of a frequency comb laser, rapid modulation of the CEO frequency can be implemented via electric modulation of the transmission or reflection loss of an additional optical element, which can be the saturable absorber itself. In another embodiment, the thin film can also be used as a saturable absorber in order to facilitate passive modelocking. In some implementations the optical element may be formed on a cleaved or polished end of an optical fiber.

Abstract: Methods, systems and apparatus are disclosed for delivery of pulsed treatment radiation by employing a pump radiation source generating picosecond pulses at a first wavelength, and a frequency-shifting resonator having a lasing medium and resonant cavity configured to receive the picosecond pulses from the pump source at the first wavelength and to emit radiation at a second wavelength in response thereto, wherein the resonant cavity of the frequency-shifting resonator has a round trip time shorter than the duration of the picosecond pulses generated by the pump radiation source. Methods, systems and apparatus are also disclosed for providing beam uniformity and a sub-harmonic resonator.

Abstract: A mode-locked laser system operable at low temperature can include an annealed, frequency-conversion crystal and a housing to maintain an annealed condition of the crystal during standard operation at the low temperature. In one embodiment, the crystal can have an increased length. First beam shaping optics can be configured to focus a beam from a light source to an elliptical cross section at a beam waist located in or proximate to the crystal. A harmonic separation block can divide an output from the crystal into beams of different frequencies separated in space. In one embodiment, the mode-locked laser system can further include second beam shaping optics configured to convert an elliptical cross section of the desired frequency beam into a beam with a desired aspect ratio, such as a circular cross section.

Abstract: Described herein is a tunable optical filter (1). The filter includes a phase manipulation layer in the form of a liquid crystal material (3) and a diffractive layer in the form of a diffraction grating (5) sandwiched between an upper glass layer (7) and lower silicon layer (9). Grating (5) includes a grating structure (11) etched therein for angularly diffracting an input optical signal into a plurality of constituent wavelength components according to wavelength. Material (3) includes a two-dimensional array of independently addressable pixels (13), each pixel configured for receiving a drive signal and, in response to the drive signal, selectively modifying the phase of the wavelength components incident onto each pixel to directionally steer the components along respective angularly separated paths. By suitable steering of the wavelength components, at least one wavelength component is coupled along a predetermined collection path to an optical system such as a laser cavity.

Abstract: A semiconductor laser apparatus is provided. The semiconductor laser apparatus includes a mode-locked semiconductor laser device and an external resonator including a dispersion compensation system, wherein the semiconductor laser apparatus is configured to generate self modulation, to introduce a negative group velocity dispersion into the external resonator, and to provide spectral filtering after the external resonator.

Abstract: Compact laser systems are disclosed which include ultrafast laser sources in combination with nonlinear crystals or waveguides. In some implementations fiber based mid-IR sources producing very short pulses and/or mid-IR sources based on a mode locked fiber lasers are utilized. A difference frequency generator receives outputs from the ultrafast sources, and generates an output including a difference frequency. The output power from the difference frequency generator can further be enhanced via the implementation of large core dispersion shifted fibers. Exemplary applications of the compact, high brightness mid-IR light sources include medical applications, spectroscopy, ranging, sensing and metrology.

Abstract: Methods and systems for delivery of high peak power optical pulses through optical fiber are disclosed. Raman soliton generation is utilized to maintain the properties of the pulses in the delivery fiber. The apparatus can comprise any high peak power pulse source and delivery fiber supporting Raman soliton generation.

Abstract: A laser device (100), configured for generating laser pulses, has a laser resonator (10) with a gain disk medium (11) and a Kerr medium (12). The laser resonator (10) includes a first mode shaping section (13) which is adapted for shaping a circulating electric field coupled into the gain disk medium (11), and a second mode shaping section (14), which is adapted for shaping the circulating electric field coupled into the Kerr medium (12) independently of the electric field shaping in the first mode shaping section (13). Furthermore, a method of generating laser pulses (1) using a laser resonator (10) with a gain disk medium (11) and a Kerr medium (12) is described.

Abstract: A mode-locked laser amplifier utilizing free-space optical feedback is provided. The amplifier may tap a portion of the input laser signal and tap a portion of the output laser signal, combine the input and output samples in a free-space coupler to form a feedback laser signal, and couple the feedback laser signal back to the input laser signal. The free-space coupler suppresses higher order modes of the output laser signal. The free-space coupler can be tunable to permit selection of the operating mode of the amplifier. A plurality of amplifiers can be utilized to form a multi-stage mode-locked amplifier system. The composite feedback signal can be coupled back to each amplifier stage to lock the operating mode.

Abstract: Techniques and devices based on optical resonators made of nonlinear optical materials and nonlinear wave mixing to generate optical combs that are stabilized relative to an atomic reference.

Abstract: A laser includes an optically pumped semiconductor OPS gain-structure. The apparatus has a laser-resonator which includes a mode-locking device for causing the laser to deliver mode-locked pulses. The resonator has a total length selected such that the mode-locked pulses are delivered at a pulse repetition frequency less than 150 MHz. An optical arrangement within the resonator provides that radiation circulating in the resonator makes a plurality of incidences on the OPS gain-structure with a time less than the excited-state lifetime of the gain-structure between successive incidences.

Abstract: Frequency standards based on mode-locked fiber lasers, fiber amplifiers and fiber-based ultra-broad bandwidth light sources, and applications of the same.

Abstract: Provided is an apparatus for generating a single-polarization mode-locked laser capable of energy control. The apparatus for generating a single-polarization mode-locked laser is configured to adjust at least one of a focal length of a lens focusing laser light on a semiconductor saturable absorber mirror (SESAM) functioning as a saturable absorber, power of pump laser light, and reflectivity of an output coupler (OC) to set fluence, which is defined as energy density per unit area of the laser light incident on the saturable absorber, to be greater than reference fluence, which is energy density per unit area of the laser light incident on the saturable absorber when reflectivity of the saturable absorber is a maximum. Accordingly, it is possible to generate a single-polarization mode-locked laser, of which energy can be controlled, without generating multiple pulses.

Abstract: In at least one embodiment of the wavelength-tunable light source (1), it comprises an output source (2), which is capable in operation of generating electromagnetic radiation (R). Furthermore, the light source (1) has a wavelength-selective first filter element (5), which is situated downstream from the output source (2). Moreover, the light source (1) contains a first amplifier medium (3), which is situated downstream from the first filter element (5) and is capable of at least partial amplification of the radiation (R) emitted by the output source (2). The light source (1) further comprises at least one wavelength-selective second filter element (6), which is situated downstream from the first amplifier medium (3), the second filter element (6) having an optical spacing (L) to the first filter element (5). The first filter element (5) and the at least one second filter element (6) are tunable via a control unit (11), which the light source (1) has.

Abstract: Apparatus and methods for anisotropic pumping of a Kerr lens modelocked laser. Direct diode laser pumping of an ultrafast Kerr lens modelocked laser oscillator is accomplished. Diode lasers generate severely anisotropic beams, meaning the pump beam has a higher-beam-quality dimension and a lower-beam-quality dimension. By spatially overlap of the pump beam higher-beam-quality dimension and the KLM laser mode, KLM operation is accomplished. Multiple laser diode pump beams are combined in counterpropagating and same-side configurations.

Abstract: Compact laser systems are disclosed which include ultrafast laser sources in combination with nonlinear crystals or waveguides. In some implementations fiber based mid-IR sources producing very short pulses and/or mid-IR sources based on a mode locked fiber lasers are utilized. A difference frequency generator receives outputs from the ultrafast sources, and generates an output including a difference frequency. The output power from the difference frequency generator can further be enhanced via the implementation of large core dispersion shifted fibers. Exemplary applications of the compact, high brightness mid-IR light sources include medical applications, spectroscopy, ranging, sensing and metrology.

Abstract: The invention relates to scanning pulsed laser systems for optical imaging. Coherent dual scanning laser systems (CDSL) are disclosed and some applications thereof. Various alternatives for implementation are illustrated, including highly integrated configurations. In at least one embodiment a coherent dual scanning laser system (CDSL) includes two passively modelocked fiber oscillators. The oscillators are configured to operate at slightly different repetition rates, such that a difference ?fr in repetition rates is small compared to the values fr1 and fr2 of the repetition rates of the oscillators. The CDSL system also includes a non-linear frequency conversion section optically connected to each oscillator. The section includes a non-linear optical element generating a frequency converted spectral output having a spectral bandwidth and a frequency comb comprising harmonics of the oscillator repetition rates.

Abstract: A laser cavity includes a gain medium for amplifying a light pulse in a light path, wherein the gain medium has a gain profile for amplifying the light pulse as a function of wavelength; at least one mirror on one side of the gain medium; and an output coupler. The output coupler has an output coupling profile for inducing loss in the light pulse as a function of wavelength that substantially matches the saturated gain profile of the gain medium across a range of lasing wavelengths. The purpose of this device is to achieve a flattened net-gain profile to substantially improve mode-locking performance with respect to self-starting, beam-quality, and broadband operation.

Abstract: Compact optical frequency sources are described. The comb source may include an intra-cavity optical element having a multi-material integrated structure with an electrically controllable active region. The active region may comprise a thin film. By way of example, the thin film and an insulating dielectric material disposed between two electrodes can provide for rapid loss modulation. In some embodiments the thin film may comprise graphene. In various embodiments of a frequency comb laser, rapid modulation of the CEO frequency can be implemented via electric modulation of the transmission or reflection loss of an additional optical element, which can be the saturable absorber itself. In another embodiment, the thin film can also be used as a saturable absorber in order to facilitate passive modelocking. In some implementations the optical element may be formed on a cleaved or polished end of an optical fiber.

Abstract: Implementations and examples of mode-locked fiber lasers based on fiber laser cavity designs that produce self-similar pulses (“similaritons”) with parabolic pulse profiles with respect to time at the output of the fiber gain media to effectuate the desired mode locking operation. An intra-cavity narrowband optical spectral filter is included in such fiber lasers to ensure the proper similariton conditions.

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: A laser includes an optically pumped semiconductor OPS gain-structure. The apparatus has a laser-resonator which includes a mode-locking device for causing the laser to deliver mode-locked pulses. The resonator has a total length selected such that the mode-locked pulses are delivered at a pulse repetition frequency of about 100 MHz. An optical arrangement within the resonator provides that radiation circulating in the resonator makes a plurality of incidences on the OPS gain-structure with a time less than the excited-state lifetime of the gain-structure between successive incidences.

Abstract: Feedback loops can be used to shift and stabilize the carrier-envelope phase of a frequency comb from a mode-locked fibers laser or other optical source. Compared to other frequency shifting and stabilization techniques, feedback-based techniques provide a wideband closed-loop servo bandwidth without optical filtering, beam pointing errors, or group velocity dispersion. It also enables phase locking to a stable reference, such as a Ti:Sapphire laser, continuous-wave microwave or optical source, or self-referencing interferometer, e.g., to within 200 mrad rms from DC to 5 MHz. In addition, stabilized frequency combs can be coherently combined with other stable signals, including other stabilized frequency combs, to synthesize optical pulse trains with pulse durations of as little as a single optical cycle. Such a coherent combination can be achieved via orthogonal control, using balanced optical cross-correlation for timing stabilization and balanced homodyne detection for phase stabilization.

Abstract: An optical coherence analysis system uses a laser swept source that is constrained to operate in a stable mode locked condition by modulating a drive current to the semiconductor optical amplifier as function of wavelength or synchronously with the drive voltage of the laser's tunable element based on stability map for the laser.

Abstract: A system includes a modulatable source and matched modal filter. The modulatable source is associated with a plurality of source modes to provide a generated signal. The matched modal filter is coupled to the modulatable source to receive the generated signal. Filter modes are to match the source modes. The matched modal filter is coupleable to a link fiber to provide a signal to the link fiber. The filter modes are to match a subset of link fiber modes to couple the plurality of filter modes to the link fiber.

Abstract: A laser diode assembly includes: a mode-locked laser diode device; a diffraction grating that configures an external resonator, returns primary or more order diffracted light to the mode-locked laser diode device, and outputs 0-order diffracted light outside; and an imaging section provided between the mode-locked laser diode device and the diffraction grating and imaging an image of a light output end face of the mode-locked laser diode device on the diffraction grating.

Abstract: The invention relates to an optical assembly (1) comprising a pulsed light source (2) for generating primary light pulses (4), a pulse splitter (5) for splitting said primary light pulses (4) into first and second secondary light pulses (7), and a delay element (8) for delaying said second secondary light pulses (7) relative to said first secondary light pulses (6), where the pulse repetition rate of said pulsed light source (2) is variable in order to change a temporal delay between different secondary light pulses (6,7) The invention is characterized in that said optical assembly (1) comprises a thermal insulation (12), a temperature stabilizer (16) or a temperature compensator (13) for said delay element (8) and/or a control circuit (27) for determining and controlling a drift of said pulse repetition rate.