Abstract: A coherent beam combination (CBC) system (10) includes an array of beam sources (12a, 12b and 12c) generating coherent beams directed towards a target (T). The phase modulators (14a, 14b and 14c) allow adjustment of relative phase offsets of the beams. A detector (16) monitors an intensity of the radiation impinging on an area of the target (T). A controller (18) receives the intensity parameter and controls a phase adjustment of the beams according to a deterministic (i.e., quantitative) measurement of a phase offset of each beam relative to a representative phase of the sum of all the other beams. This is achieved by using interferometric techniques, referred to herein as Target In-the-Loop Interferometry (TILI).

Abstract: An imaging subsystem is disclosed, wherein the imaging subsystem is coherent and it generally includes an optical phased array (OPA), frequency modulation (FM) and/or amplitude modulation (AM). The imaging subsystem is operable with a Super System on Chip (SSoC) or a photonic neural learning processor (PNLP). The Super System on Chip (SSoC) includes memristors. The imaging subsystem is further operable with a camera (e.g., a metamaterial camera, wherein the metamaterial camera includes one or more metasurfaces). Furthermore, the imaging subsystem may be included with a vehicle system, wherein the vehicle system can recommend a service or an offer to a user/driver by anticipating any need of the user/driver.

Abstract: A laser system including a seed laser, a laser beam splitting and combining subsystem receiving an output from the seed laser and providing a combined laser output having noise and a noise cancellation subsystem operative to provide a noise cancellation phase correction output based on taking into consideration the noise at intermittent times, the laser beam splitting and combining subsystem varying a phase of the combined laser output during time interstices between the intermittent times.

Abstract: Systems and methods described herein are directed to optical light sources, such as an external cavity laser (ECL) with an active phase shifter. The system may include control circuitry for controlling one or more parameters associated with the active phase shifter. The phase shifter may be a p-i-n phase shifter. The control circuitry may cause variation in a refractive index associated with the phase shifter, thereby varying a lasing frequency of the ECL. The ECL may be configured to operate as a light source for a light detection and ranging (LIDAR) system based on generating frequency modulated light signals. In some embodiments, the ECL may generate an output LIDAR signal with alternating segments of increasing and decreasing chirp frequencies. The ECL may exhibit increased stability and improved chirp linearities with less dependence on ambient temperature fluctuations.

Abstract: A method includes determining a number of drive pulses of equal width and amplitude that would drive LEDs with a total charge during a frame. If the width of the drive pulses is greater than a minimum-width and less than a maximum-width, the LEDs are driven with the drive pulses. If the width of the drive pulses is less than the minimum-width and an amplitude of the drive pulses is greater than a minimum-amplitude, decrement the amplitude of the drive pulses and recalculate the width of the drive pulses so each drive pulse has the decremented amplitude and recalculated width. If the amplitude of the drive pulses is equal to the minimum-amplitude, reduce the number of drive pulses and recalculate the width and amplitude of the reduced number of drive pulses. If the amplitude of the drive pulses is equal to the minimum-amplitude, the LEDs are not driven.

Abstract: A fiber amplifier system including a plurality of seed beam sources each generating a seed beam at a different wavelength and a selection switch selectively outputting the seed beams on one or more outputs. The system also includes a plurality of fiber amplifiers each receiving one of the selected seed beams from the selection switch and a plurality of wavelength division multiplexers (WDMs) where a separate WDM receives an amplified beam from a fiber amplifier, each WDM providing the amplified beam on a separate output depending on the wavelength of the selected beam. The system further includes a plurality of beam directors each being coupled to each WDM, where one of the beam directors receives all of the amplified beams on the delivery fibers from each of the WDMs depending on the selected seed beam, each beam director combining the beams using CBC or SBC into a combined output beam.

Abstract: A multi-beam combining apparatus includes a phase shifting section, a superposing section, an observing section and a phase control section. The phase shifting section generates a plurality of phase-shifted laser beams by shifting the phase of each of the plurality of laser beams. The superposing section generates a plurality of superposed laser beam by superposing the reference laser beam and each of the plurality of phase-shifted laser beams. The observing section generates interference pattern data of a spatial interference pattern which appears when observing each of the superposed laser beams. The phase control section carries out a feedback control of the phase shifts in the phase shifting section based on the interference pattern data obtained for every superposed laser beam, and thereby sets the plurality of phase-shifted laser beams to desired states.

Abstract: A laser apparatus may include a seed laser device configured to output a pulse laser beam, a pulse energy adjusting unit configured to vary pulse energy of the pulse laser beam, at least one amplifier for amplifying the pulse laser beam, at least one power source for varying an excitation intensity in the at least one amplifier, and a controller configured to control the pulse energy adjusting unit on a pulse-to-pulse basis for the pulse laser beam passing therethrough and to control the at least one power source for a group of multiple pulses of the pulse laser beam.

Abstract: Embodiments of the present invention use an external cavity laser source with dual input terminals, such as bias current for a gain section, and a voltage signal for a modulator section. An aspect of the present invention provides an ultra-low frequency noise external cavity frequency modulated (FM) semiconductor laser source frequency stabilized by a dual electronic feedback circuitry applied to semiconductor gain section and a modulation section. A further aspect of the present invention provides an optical frequency discriminator based on homodyne phase demodulation using an unbalanced Michelson interferometer with fiber optics delay and a symmetrical 3×3 optical coupler.

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 scanning laser projector includes a scanning mirror that moves in a sinusoidal motion on at least one axis. Pixels are displayed by modulating a laser beam that is reflected by the scanning mirror. Pixels are generated using light pulses of different duty cycles based on the position and/or angular velocity of the laser beam.

Abstract: A method and device are provided for generating bursts of sub-pulses, preferably in the picosecond range. Seed pulses are first generated, and then phase modulated to spread their spectral profile to several time-dependent spectral components. The phase modulated seed pulses are then spectrally filtered to remove spectral components and retain only selected ones, creating gaps in the amplitude profile of the seed pulses which therefore form bursts of sub-pulses. Various parameters such as the modulation amplitude, the modulation frequency, the spectral characteristics of the filters and the overall amplitude of the seed pulses may be controlled to provide a great versatility and adaptability.

Abstract: In one embodiment, a system includes a master oscillator for generating a primary laser signal. A plurality of amplifiers amplifies a plurality of secondary laser signals and generates a plurality of amplified laser signals. A plurality of actuators adjusts a position, a beam angle, a path length, and a phase of the plurality of amplified laser signals. At least one control module controls the plurality of actuators that adjust the position, the beam angle, the path length, and the phase of the plurality of amplified laser signals. A combiner receives the amplified laser signals to generate a combined laser output signal. At least one filter samples the combined laser output signal to generate a plurality of phase errors as feedback for the control module to control at least one of the position, the beam angle, or the path length for the plurality of amplified laser signals.

Abstract: A wavelength-tunable laser system includes an optical fiber collimator array having at least two ports, an optical amplifier connected to one port of an optical fiber, an optical coupler for coupling light incident from the optical amplifier and transmitting the coupled light to another port, a diffraction grating plate for guiding each wavelength component of light incident from the optical fiber collimator array in a different direction, and an Opto-Very Large Scale Integration (Opto-VLSI) processor.

Abstract: High-power, phased-locked, laser arrays as disclosed herein utilize a system of optical elements that may be external to the laser oscillator array. Such an external optical system may achieve mutually coherent operation of all the emitters in a laser array, and coherent combination of the output of all the lasers in the array into a single beam. Such an “external gain harness” system may include: an optical lens/mirror system that mixes the output of all the emitters in the array; a holographic optical element that combines the output of all the lasers in the array, and an output coupler that selects a single path for the combined output and also selects a common operating frequency for all the coupled gain regions.

Abstract: A semiconductor laser module includes a semiconductor device including a semiconductor laser and a bending waveguide through which a laser light emitted from the semiconductor laser propagates, a beam splitter splitting the laser light into a first laser light and a second laser light, a plurality of detectors respectively arranged at different positions in a cross section of a light flux of the second laser light to detect the second laser light, and a waveform shaping unit provided on an optical path of the laser light. The waveform shaping unit is configured to make a relation between an output of the semiconductor laser and detection values of the detectors approach a linear relation.

Abstract: The aim of the present disclosure is to enable a fast CE phase evaluation of the laser pulses, in particular in real time, including for multi-cycle pulses. Said aim is achieved by providing a polarization gating stage (8) for changing the laser pulses (7) to be evaluated in the phase and subsequent phase evaluation stage (15) for measuring the phase position of the changed laser pulses. The descriptions in the present disclosure can be used for example in laser technology for producing and monitoring single-cycle pulses.

Abstract: An optoelectronic swept-frequency semiconductor laser coupled to a microfabricated optical biomolecular sensor with integrated resonator and waveguide and methods related thereto are described. Biomolecular sensors with optical resonator microfabricated with integrated waveguide operation can be in a microfluidic flow cell.

Abstract: A method for implementing a coherent laser beam combining system in which a master laser oscillator output is split into N signals, fed through N phase adjusters and N amplifiers and combined in a coherent power combiner. The output of the combiner is sampled and sent to a processor. The processor selects one of the N phase adjusters, sweeps the phase in small steps over a 2? range, and locks the phase of that adjuster to the phase that corresponds to the maximum value of the combiner sample for that sweep cycle. The process is repeated for all the remaining phase adjusters resulting in maximizing the combiner output. The sweep cycles are repeated continuously to correct any phase errors that may occur over time. A similar method can be used in which both the polarizations and the phases of the N signals are maximized to thereby maximize the output of the coherent power combiner.

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: The present disclosure relates to a method and to a device (1) by which a train (2, 2) of short laser pulses of a mode-coupled laser (3) is compensated with respect to the carrier envelope offset frequency of the individual lines contained in the associated frequency comb. The aim of the disclosure is to determine the carrier envelope offset frequency and to utilize said frequency to operate an acousto-optical frequency shifter (13). In said shifter, the uncompensated train of temporally equidistantly short laser pulses is diffracted in a first order such that the individual lines of the frequency comb are shifted by the carrier envelope offset frequency. The resulting compensated train of short laser pulses has a frequency comb, the individual lines of which are integral multiples of the repetition frequency of the individual light pulses in the train of short laser pulses.

Abstract: High-power, phased-locked, laser arrays as disclosed herein utilize a system of optical elements that may be external to the laser oscillator array. Such an external optical system may achieve mutually coherent operation of all the emitters in a laser array, and coherent combination of the output of all the lasers in the array into a single beam. Such an “external gain harness” system may include: an optical lens/mirror system that mixes the output of all the emitters in the array; a holographic optical element that combines the output of all the lasers in the array, and an output coupler that selects a single path for the combined output and also selects a common operating frequency for all the coupled gain regions.

Abstract: Devices and techniques for locking a laser in frequency by locking a reference laser to a reference frequency and an optical interferometer to the reference laser and by locking the laser to a selected frequency produced by the optical interferometer.

Abstract: Particular embodiments of the present invention relate generally to semiconductor lasers and laser projections systems and, more particularly, to schemes for controlling semiconductor lasers. According to one embodiment of the present invention, a laser having a gain section, a phase section and a wavelength selective section is configured for optical emission of encoded data. The optical emission is shifted across a plurality of laser cavity modes by applying a quasi-periodic phase shifting signal I/V? to the phase section of the semiconductor laser. The amplitude of the quasi-periodic signal transitions periodically between a maximum drive level and a minimum drive level at a frequency that varies randomly over time.

Abstract: A fiber laser amplifier system including a plurality of master oscillators each generating a signal beam at a different wavelength. A splitter is provided for each master oscillator that splits the signal beam into a plurality of fiber beams where a separate fiber beam is sent to a fiber amplifier. A tapered fiber bundle couples the output ends the fiber amplifiers for each wavelength group into a combined fiber providing a combined output beam, where a separate combined output beam is provided for the wavelength for each master oscillator. An end cap is optically coupled to an output end of each of the tapered fiber bundles to expand the combined output beam. A spectral beam combination grating receives the combined beams from the tapered fiber bundles at different angles and outputs an output beam of all of the combined beams as a single beam being directed in the same direction.

Abstract: This invention relates to opto-electronic systems using semiconductor lasers driven by optical phase-locked loops that control the laser's optical phase and frequency. Feedback control provides a means for precise, wideband control of optical frequency and phase, augmented further by four wave mixing stages and digitally stitched independent optical waveforms for enhanced tunability.

Abstract: A laser system comprises: a seed oscillator, having a seed output; dispersive optics, operative to receive the seed output and divide the seed output into spectrally separate seed components; an array of individually addressable, phase adjustable laser amplifiers corresponding to the spectrally separate components, each laser amplifier receiving as its seed one of the spectrally separate seed components and producing one of the spectrally separate amplified components; and phase actuators controlling the individually addressable, phase adjustable laser amplifiers. A method of operating a laser system comprises: generating a seed signal; dividing the seed signal into spectrally separate component signals; amplifying the spectrally separate component signals; recombining the spectrally separate component signals into an amplified output; and controlling phases of the amplified spectrally separate component signals. Both single-pass and double-pass amplifier array versions are disclosed.

Abstract: A modulation method according to the invention is applied to a modulation device in which a light source is driven by a differential signal while a modulation circuit and the light source are capacitively coupled. In the modulation method of the invention, when an average potential fluctuates at an input terminal of the light source, a potential fluctuation is externally provided using a control circuit such that a normal phase side and a reverse phase side become equal to each other in a time constant of the fluctuation in average potential, and transient states of the average potentials at the normal phase side and reverse phase side are equalized and cancel each other as in-phase components of a signal input to the light source, which allows an optical signal to be normally transmitted from the light source.

Abstract: A semiconductor laser module includes a semiconductor device including a semiconductor laser and a bending waveguide through which a laser light emitted from the semiconductor laser propagates, a beam splitter splitting the laser light into a first laser light and a second laser light, a plurality of detectors respectively arranged at different positions in a cross section of a light flux of the second laser light to detect the second laser light, and a waveform shaping unit provided on an optical path of the laser light. The waveform shaping unit is configured to make a relation between an output of the semiconductor laser and detection values of the detectors approach a linear relation.

Abstract: According to the present inventions, a phase control device for laser light pulse includes a laser, a reference comparator, a measurement comparator, a phase difference detector and a loop filter. The laser outputs a laser light pulse. The reference comparator compares a voltage of a reference electric signal having a predetermined frequency and a predetermined voltage with each other, thereby outputting a result thereof. The measurement comparator compares a voltage based on a light intensity of the laser light pulse and a voltage of a measurement electric signal having the predetermined frequency, with a voltage of a phase control signal, thereby outputting a result thereof. The phase difference detector detects a phase difference between the output from the reference comparator and the output from the measurement comparator. The loop filter removes a high frequency component of an output from the phase difference detector.

Abstract: A laser device capable of preventing deterioration of a light signal and a controlling method therefor are provided.

Abstract: This invention relates to opto-electronic systems using semiconductor lasers driven by optical phase-locked loops that control the laser's optical phase and frequency. Feedback control provides a means for precise control of optical frequency and phase, including the ability for broadband electronic tunability of optical signals and the cascading of multiple lasers for enhanced tunability and coherent combining for increased output power.

Abstract: A multi-beam laser beam control system includes a laser transmitter configured to emit light in a plurality of beamlets. A sensor is configured to receive light from the beamlets. A processor is communicably coupled to the sensor and configured to compute a relative phase of a wavefront of at least one beamlet based on output from the sensor. A controller is communicably coupled to the processor and to the laser transmitter. The controller is configured to adjust a phase of at least one of the beamlets.

Abstract: A laser device includes a cavity and a control portion. The cavity has an optical amplifier, a wavelength selectable portion having a changeable transmission wavelength range, and a mirror. The control portion controls the wavelength selectable portion so that the transmission wavelength range of the wavelength selectable portion is changed to a given range. The control portion controls the wavelength selectable portion so that the cavity outputs a desirable lasing wavelength light and optical intensity of the desirable lasing wavelength light is a given value, after controlling the wavelength selectable portion so that the cavity outputs the desirable lasing wavelength light.

Abstract: High power optical pulses generating methods and laser oscillators are provided. A light generating module generates seed optical pulses having predetermined optical characteristics. A spectrum tailoring module is then used to tailor the spectral profile of the optical pulses. The spectral tailoring module includes a phase modulator which imposes a time-dependent phase variation on the optical pulses. The activation of the phase modulator is synchronized with the passage of the optical pulse therethough, thereby efficiently reducing the RF power necessary to operate the device.

Abstract: A method and system for stabilizing a laser to a frequency reference with an adjustable offset. The method locks a sideband signal generated by passing an incoming laser beam through the phase modulator to a frequency reference, and adjusts a carrier frequency relative to the locked sideband signal by changing a phase modulation frequency input to the phase modulator. The sideband signal can be a single sideband (SSB), dual sideband (DSB), or an electronic sideband (ESB) signal. Two separate electro-optic modulators can produce the DSB signal. The two electro-optic modulators can be a broadband modulator and a resonant modulator. With a DSB signal, the method can introduce two sinusoidal phase modulations at the phase modulator. With ESB signals, the method can further drive the optical phase modulator with an electrical signal with nominal frequency ?1 that is phase modulated at a frequency ?2.

Abstract: High-power, phased-locked, laser arrays as disclosed herein utilize a system of optical elements that may be external to the laser oscillator array. Such an external optical system may achieve mutually coherent operation of all the emitters in a laser array, and coherent combination of the output of all the lasers in the array into a single beam. Such an “external gain harness” system may include: an optical lens/mirror system that mixes the output of all the emitters in the array; a holographic optical element that combines the output of all the lasers in the array, and an output coupler that selects a single path for the combined output and also selects a common operating frequency for all the coupled gain regions.

Abstract: Pulses of signals in the terahertz region are generated using an apparatus made up of a mode-locked semiconductor laser diode with a short duty cycle that is optically coupled to a biased Auston switch. The output from the mode-locked semiconductor laser diode may first be supplied to a pulse compressor, and the resulting compressed pulses supplied to the Auston switch. Preferably, the mode-locking of the semiconductor laser diode is controllable, i.e., it is an active mode-locking semiconductor laser, so that the phase of the output optical signal from the laser is locked to the phase of an input control signal.

Abstract: All-optical quasi-phase matching (QPM) uses a train of counterpropagating pulses to enhance high-order harmonic generation (HHG) in a hollow waveguide. A pump pulse enters one end of the waveguide, and causes HHG in the waveguide. The counterpropagation pulses enter the other end of the waveguide and interact with the pump pulses to cause QPM within the waveguide, enhancing the HHG.

Abstract: A DBR semiconductor laser is controlled in an image projecting apparatus, which includes the DBR laser having a phase and DBR region, a light wavelength converting device for converting fundamental-wave light emitted from the DBR laser into second harmonic wave light, an optical deflector for scanning the second harmonic wave in a one or two-dimensional manner, and a modulating portion for modulating the DBR laser. Coefficient calculating and wavelength adjusting steps are performed within a non-drawing time. The coefficient calculating step calculates at least one coefficient in a relationship between a DBR current to be injected into the DBR region and a phase current to be injected into the phase region for continuously shifting the wavelength of the fundamental-wave light. The wavelength adjusting step changes DBR current injected into the DBR region and phase current injected into the phase region based on the relationship.

Abstract: Systems and methods for pre-correcting accumulated optical nonlinear phase error in a shaped optical pulse derived from a continuous wave laser signal are provided. A continuous wave laser signal is received. A pulse signal is received. A shaped optical pulse is generated from the continuous wave laser signal upon being driven by the pulse signal. A pulse intensity level to be applied to the phase of the shaped optical pulse is received. A phase correcting signal is generated based on the pulse intensity level. Application of the phase correcting signal to the shaped optical pulse is time-synchronized and the phase correcting signal is applied to the shaped optical pulse to generate a pre-corrected shaped optical pulse.

Abstract: Provided is a semiconductor laser device including: a gain area where multi-wavelength lights are generated and gain are provided; a first reflection area where among the multi-wavelength lights, a first-wavelength light is reflected to the gain area in response to a first selection signal; a second reflection area where among the multi-wavelength lights, a second-wavelength light is reflected to the gain area; and a phase control area where a phase of the second-wavelength light is shifted in response to a phase control signal, the phase control area being disposed between the first reflection layer and the second reflection layer.

Abstract: Systems and methods for pre-correcting accumulated optical nonlinear phase error in a shaped optical pulse derived from a continuous wave laser signal are provided. A continuous wave laser signal is received. A pulse signal is received. A shaped optical pulse is generated from the continuous wave laser signal upon being driven by the pulse signal. A pulse intensity level to be applied to the phase of the shaped optical pulse is received. A phase correcting signal is generated based on the pulse intensity level. Application of the phase correcting signal to the shaped optical pulse is time-synchronized and the phase correcting signal is applied to the shaped optical pulse to generate a pre-corrected shaped optical pulse.

Abstract: A gain element and a variable wavelength reflector form a resonator. A wavelength selective element selects a resonance wavelength in the resonator. A beam splitter is provided for monitoring an incident light from the gain element and a reflected light from the variable wavelength reflector. A phase adjustment element is arranged in the resonator. A wavelength-lock control unit locks the resonance wavelength to a desired resonance wavelength by adjusting the phase of the resonance wavelength based on the monitored incident light and by adjusting the variable wavelength reflector based on a ratio between the incident light and the reflected light.

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 silicon-on-insulator (SOI)-based tunable laser is formed to include the gain medium (such as a semiconductor optical amplifier) disposed within a cavity formed within the SOI substrate. A tunable wavelength reflecting element and associated phase matching element are formed on the surface of the SOI structure, with optical waveguides formed in the surface SOI layer providing the communication between these components. The tunable wavelength element is controlled to adjust the optical wavelength. Separate discrete lensing elements may be disposed in the cavity with the gain medium, providing efficient coupling of the optical signal into the SOI waveguides. Alternatively, the gain medium itself may be formed to include spot converting tapers on its endfaces, the tapers used to provide mode matching into the associated optical waveguides.

Abstract: The object is to provide a highly reliable, high-performance, and low-price tunable light source and the like. The present invention comprises: a multiple resonator that oscillates with a wavelength where frequencies of three or more resonant elements with shifted cycles intersect; and a tunable device for controlling the resonant wavelength of the multiple resonator by simultaneously changing the respective optical path lengths of the plurality of resonant elements constituting the multiple resonator.

Abstract: A lighting unit (100) having a divergent coherent light source (104, 106) is provided for the generation of an at least locally irregular pattern (20) in a monitored zone (12). In this respect, the lighting unit (100) has an optical phase element (108, 110) in the beam path of the light source (104, 106), said optical phase element having unevenness made to generate local phase differences between light portions incident at the phase element at adjacent positions and thus to generate the irregular pattern (20) by interference.

Abstract: The present invention relates to a method and device for reducing the phase noise of a laser signal from a laser source. This device comprises a first current generator for supplying a driving current to the laser source in view of producing the laser signal. A phase noise detector is responsive to the laser wavelength for generating a phase error signal and a second current generator is responsive to the phase error signal for generating a compensation current added to the driving current supplied to the laser source for generating a phase-adjusted laser signal. The device therefore defines a phase stabilization loop formed by the phase noise detector and the second current generator, for reducing the phase noise of the laser signal.

Abstract: According to one embodiment of the present invention, a method of operating a laser source is provided. The laser source comprises a laser configured to generate an optical signal, and a polarization split and delay unit that is coupled to the optical signal. The polarization split and delay unit is configured to split the optical signal into a first and second orthogonally polarized component, create an optical path difference ?L between the first and second orthogonally polarized components and combine the first and second orthogonally polarized components into a combined signal. The method comprises modulating the optical signal by applying a wavelength modulation signal to the laser such that the modulated optical signal comprises at least a first wavelength ?1 and a second wavelength ?2, wherein the first wavelength ?1 and the second wavelength ?2 are separated by a wavelength difference ??.