Abstract: The present invention relates to an apparatus for generating an ultra-short ultra-high intensity pulse laser, comprising: a pulse laser providing unit which generates an ultra-short ultra-high intensity pulse laser, stretches pulse width, then selects and provides only a pulse laser having a predetermined polarizing angle; a polarization characteristic adjusting unit which divides the pulse laser provided by the pulse laser providing unit into S-polarizing component light and P-polarizing component light, varies the phase difference and amplitude difference between the S-polarizing component light and the P-polarizing component light, and combines the two types of light to generate a pulse laser with varied polarization characteristics; and a pulse compression unit which compresses the pulse width of the pulse laser, the polarization characteristics of which are varied by the polarization characteristic adjusting unit, and outputs the pulse laser.

Abstract: Loss modulated silicon evanescent lasers are disclosed. A loss-modulated semiconductor laser device in accordance with one or more embodiments of the present invention comprises a semiconductor-on-insulator (SOI) structure resident on a first substrate, the SOI structure comprising a waveguide in a semiconductor layer of the SOI structure, and a semiconductor structure bonded to the semiconductor layer of the SOI structure, wherein at least one region in the semiconductor layer of the SOI structure controls a photon lifetime in the semiconductor laser device.

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 system and a method for controlling the quality of an industrial process, of the type that comprises the steps of: providing one or more reference signals for the industrial process; acquiring one or more real signals that are indicative of the quality of said industrial process; and comparing said one or more reference signals with said one or more real signals in order to identify defects in said industrial process.

Abstract: Systems and methods are provided for an optical modulation feedback circuit. The feedback circuit includes a low frequency comparison circuit configured to receive a monitoring signal generated by an optical detector, the monitoring signal being proportional to an amount of light generated by an optical transmission device that transmits based on a data signal that is received by an optical driver. The comparison circuit is further configured to generate a modulation control feedback signal that is transmitted to the optical driver based on a comparison of a low frequency component of the monitoring signal and a low frequency component of the data signal.

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: Apparatus for combining laser radiation (1) 5 which apparatus comprises a seed laser (2), a splitter (3), a plurality of amplifier chains (4), a reference amplifier chain (7), detection means (5). demodulator means (6), and phase control means (12), wherein each of the amplifier chains (4) comprises at least one optical amplifier (11), optical radiation (17) emitted from the seed laser (2) is split into the plurality of amplifier chains (4) by the splitter (3).

Abstract: A method and apparatus recycle residual energy in an optical parametric burst source.

Abstract: A multibeam coherent laser diode source comprises a master laser, a linear amplifier and two perpendicular amplifiers. The master laser and amplifiers are in the form of a single heterostructure containing an active layer, two limiting layers and a radiation influx area with an influx layer. The heterostructure is characterized by the ratio of the refractive index of the heterostructure to the refractive index of influx layer. This ratio is determined from a range extending from one plus delta to one minus gamma, where delta and gamma are defined by a number much less than one and gamma is greater than delta. The linear amplifier is positioned so that optical axis of radiation propagation from master laser coincides with the axis of the linear amplifier. Each perpendicular amplifier has output edge and is positioned so that its optical axis is situated at right angle to the axis of linear amplifier.

Abstract: The pulse light source comprises a seed light source, a first YbDF, a band-pass filter, a second YbDF, and a third YbDF, and has the MOPA structure. The band-pass filter inputs pulse light which is outputted from the seed light source and amplified by the first stage YbDF, and outputs, while separating a wavelength band of the inputted pulse light into a shorter wavelength side and a longer wavelength side with reference to a peak wavelength of the inputted pulse light, the attenuated pulse light after attenuating the optical power on one side more than the optical power on the other side between the shorter and longer wavelength sides.

Abstract: A laser apparatus may include a master oscillator configured to output a laser beam, at least one amplifier disposed in a beam path of the laser beam from the master oscillator, at least one power source for applying a high-frequency voltage to the at least one amplifier, and a controller for varying the high-frequency voltage to be applied to the at least one amplifier from the at least one power source.

Abstract: An EUV light generation system includes a driver laser comprising a master oscillator such as a semiconductor laser, a spatial filter, gas slab amplification devices, relay optical systems, and high-speed axial-flow amplifiers. The slab amplification devices include beam adjusting optical units disposed, respectively, at input and output sides of the slab amplifiers SA to convert the beam profile and/or polarization direction and/or an elongated direction of the beam profile with the slab amplifiers is parallel to a free space axis AF of the slab waveguides, i.e. parallel to the discharge electrodes.

Abstract: The present invention relates to a light source control method capable of decreasing the dependence of a pulse width (FWHM) of an output pulsed light on a repetition frequency. A pulsed light source has an MOPA structure, and has a seed light source and an optical fiber amplifier. The seed light source includes a semiconductor laser which is directly modulated and outputs a pulsed light. By adjusting a temperature of the seed light source and a pumping light power of the optical fiber amplifier, a predetermined full width half maximum of a pulse at a predetermined repetition frequency is implemented for the pulsed light outputted from the optical fiber amplifier.

Abstract: The present invention discloses a method and device for the bias control of an MZ modulator. The method comprises: during startup of an MZ modulator, inputting a linearly changing bias control voltage to the bias electrode of the MZ modulator and obtaining the output optical power of the MZ modulator so as to determine a bias control voltage corresponding to a preset operating point; then enabling a communication electrical signal to be input to the radio frequency electrode of the MZ modulator, carrying out an amplitude modulation on the communication electrical signal by a low-frequency sinusoidal pilot signal, and inputting the determined bias control voltage to the bias electrode simultaneously; and sampling the output optical signals of the MZ modulator, comparing the sampled optical signal with the pilot signal, and adjusting the bias control voltage input to the bias electrode according to the result of the comparison.

Abstract: A laser light source 1 is provided with a first reflection mirror 11, a laser medium 12, an aperture 13, an output mirror 14, a half mirror 15, a light beam diameter adjuster 16, and a second reflection mirror 17, and outputs laser oscillation light 31 reflected by the half mirror 15 to the outside. The main resonator is composed by the first reflection mirror 11 and the output mirror 14 disposed so as to be opposed to each other with the laser medium 12 placed therebetween. The external resonator is composed by the output mirror 14 and the second reflection mirror 17 disposed so as to be opposed to each other. The second reflection mirror 17 is configured such that it gives amplitude or phase variations to respective positions in the section of a light beam when the light is reflected, the second reflection mirror presents an amplitude or phase variation distribution, and determines the transverse mode of the laser oscillation light 31 based on the amplitude or phase variation distribution.

Abstract: A laser device for an exposure apparatus may include: a MOPA-type or MOPO-type laser device including a seed laser and at least one gas discharge-pumped amplifier stage that receives output light from the seed laser as an input, amplifies the light, and outputs the amplified light; and at least one of a laser gas control device that at least changes the total pressure of a laser gas in said amplifier stage in accordance with requested energy and a laser power source control device that at least changes pump intensity of discharge electrodes in said amplifier stage in accordance with said requested energy, in a case where the energy of laser output light from said laser device is to be changed discontinuously in response to a request from an exposure apparatus,

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: Apparatus and method for generating controlled-linewidth laser-seed-signals for high-powered fiber-laser amplifier systems. In some embodiments, the natural chirp (frequency change of laser light over a short start-up time) of a DBR laser diode when driven by pulsed current is used to broaden the linewidth of the laser output, while adjusting the peak current and/or the pulse duration to obtain the desired linewidth.

Abstract: Methods stabilize the output of a pulsed laser system using pulse shaping capabilities. In some embodiments, transient effects following a transition between a QCW regime and a pulse shaping regime are mitigated by ensuring that the average QCW optical power substantially corresponds to the average pulsed optical power outputted in a steady-state operation of the pulsed laser system in the pulse shaping regime. The QCW signal or the pulse shaping signal may be adapted for this purpose. In other embodiments, transient effects associated with non-process pulses emitted between series of consecutive process pulses are mitigated through the proper use of sequential pulse shaping.

Abstract: The invention relates to a light emitter adapted for emitting light with a predefined angular color point distribution, to a method of use for a light emitter in video flash applications, in automotive headlight applications and/or in automotive lamp applications, and to a method, adapted for generating light with a predefined angular color point distribution.

Abstract: The present invention provides an external resonator-type wavelength tunable laser device that can properly fulfill a wavelength tuning function even with the use of a planar wavelength tunable reflector involving a considerable level of residual reflection. The external resonator-type wavelength tunable laser device includes a planar reflection structure enabling a reflection spectral peak wavelength to be varied and a semiconductor element as a semiconductor gain medium. The semiconductor gain medium is composed of a multiple quantum well in which product ?·L of optical confinement constant ? and semiconductor gain medium length L (?m) of a gain layer is at least 25 ?m and at most 40 ?m and in which gain peak wavelength ?0 (nm) observed during carrier injected with a maximum modal gain equal to an internal loss of the semiconductor gain medium is larger than ?3·?R/2+(?c+35) and smaller than (?(?·L)/7+8)·?R+(?(?·L)+?c+45).

Abstract: A multibeam coherent laser diode source comprises a master laser, a linear amplifier and two perpendicular amplifiers. The master laser and amplifiers are in the form of a single heterostructure containing an active layer, two limiting layers and a radiation influx area with an influx layer. The heterostructure is characterized by the ratio of the refractive index (n?) of the heterostructure to the refractive index (nBT) of the influx layer. The ratio n?:nBT is determined from a range extending from one plus delta to one minus gamma, where delta and gamma are defined by a number much less than one and gamma is greater than delta. The linear amplifier is positioned so that the optical axis of radiation propagation from the master laser coincides with the axis of the linear amplifier. Each perpendicular amplifier has an output edge and is positioned so that its optical axis is situated at a right angle to the axis of the linear amplifier.

Abstract: A chirped pulse amplification system includes one or more polarization compensator configured to compensate for polarization altering elements with the chirped pulse amplification system. The polarization compensator is responsive to a sensor configured to provide feedback to the polarization compensator. In some embodiments, the chirped pulse amplification system further includes a controller configured to automatically adjust the polarization compensator responsive to the sensor. The sensor is optionally a power sensor.

Abstract: A laser amplifier includes a laser active slab with a source of pump power to amplify an input laser beam, the laser active slab including a block of laser active material having opposed lateral faces defining a wedge lateral dihedral angle, opposed longitudinal faces, and opposed parallel transverse faces, the wedge lateral dihedral angle specified to minimize parasitic amplified spontaneous emission. The source of pump power may be one or more laser diode bars and microlenses producing a gain sheet in the laser active slab. The lateral faces may include optical coatings highly transmitting at a wavelength of the pump power and highly reflecting at a lasing wavelength to provide a folded path for the input laser beam though the gain sheet.

Abstract: Systems and methods have been provided to increase output power, as well as spatial and/or spectral brightness when utilizing or combining a plurality of laser elements.

Abstract: The present invention relates to an optical amplifier module, or the like, having a structure for enabling effective suppression of photodarkening and efficient optical amplification. The optical amplifier module comprises a first optical amplification waveguide which is comprised of a phosphate glass as a main component and includes a ytterbium-doped first optical waveguide region, a second optical amplification waveguide which is optically coupled to the first optical amplification waveguide and includes a ytterbium-doped second optical waveguide region which is co-doped with aluminum, and pumping light source units which supply pumping light respectively to the first optical amplification waveguide and the second optical amplification waveguide. The light to be amplified, having inputted to the first optical amplification waveguide, is amplified only once by means of the pumping light, in each of the first optical amplification waveguide and the second optical amplification waveguide.

Abstract: Apparatus and method for generating controlled-linewidth laser-seed-signals for high-powered fiber-laser amplifier systems. In some embodiments, the natural chirp (frequency change of laser light over a short start-up time) of a DBR laser diode when driven by pulsed current is used to broaden the linewidth of the laser output, while adjusting the peak current and/or the pulse duration to obtain the desired linewidth.

Abstract: A medical laser device is described that generates a laser beam controllable with presets as to pulse duration, pulse repetition rate, power and energy per pulse. The device also provides presets with respect to water and air outputs. Parametric values for power, pulse duration, pulse repetition rate, and energy per pulse as well as for water and air settings may be programmed by an end user and stored as presets.

Abstract: A continuously pumped, mode-locked laser is disclosed, which includes a cavity dumper that can remove a constant fraction of the light from the cavity at every 1/f period of time, independent of the time at which the first pulse in a train is initiated. The cavity dumper includes a modulator and two output arms, denoted as a primary output arm and a secondary output arm. When a user desires a train of pulses, the pulses are directed to the primary output arm. Between trains of pulses, when no pulse is desired by the user, the pulses are directed to the secondary output arm, which terminates in an absorber or at a secondary optical system. In this manner, the energy contained in each output pulse is essentially constant, from pulse-to-pulse and from train-to-train. This may overcome the disadvantage of many lasers that have a single output arm, in which the first pulse in a train may have an energy that depends on the length of the inactive period that immediately precedes the train.

Abstract: Fast on-line electro-optical detection of wafer defects by illuminating with a short light pulse from a repetitively pulsed laser, a section of the wafer while it is moved across the field of view of an imaging system, and imaging the moving wafer onto a focal plane assembly, optically forming a continuous surface of photo-detectors at the focal plane of the optical imaging system. The continuously moving wafer is illuminated by a laser pulse of duration significantly shorter than the pixel dwell time, such that there is effectively no image smear during the wafer motion. The laser pulse has sufficient energy and brightness to impart the necessary illumination to each sequentially inspected field of view required for creating an image of the inspected wafer die. A novel fiber optical illumination delivery system, which is effective in reducing the effects of source coherence is described.

Abstract: A laser device that includes a dual pulse-width laser-pumping circuit generates long and short laser pulses. The laser-pumping circuit employs a single power supply with dual high voltage outputs that are selectable under control of a user. The laser device conveniently generates long and short laser pulses or a mix of the two for performing specialized surgical procedures.

Abstract: It is an object to provide a laser apparatus, a laser irradiating method and a manufacturing method of a semiconductor device that make laser energy more stable. To attain the object, a part of laser beam emitted from an oscillator is sampled to generate an electric signal that contains as data energy fluctuation of a laser beam. The electric signal is subjected to signal processing to calculate the frequency, amplitude, and phase of the energy fluctuation of the laser beam.

Abstract: Exemplary embodiments provide a method and system for controlling laser power in an optical disc drive. The exemplary embodiment of a control system includes at least one control component for generating a control signal; a plant for generating a control output responsive to the control signal; and a dual feedback control loop coupled between the control output of the plant and the control component, the dual feedback control loop comprising a combination of a running optimal power control (ROPC) loop, and an automatic power control (APC) loop that run concurrently for generating respective feedback control signals that are input to the control component for generation of a combined control signal adjustment that is used at least in part to generate the control signal.

Abstract: A method and circuit is disclosed for a laser system wherein the power of the laser signal is kept at a constant near optimum value and a portion of an frequency doubled output signal is monitored and detected so that noise within the frequency doubled output signal can be minimized. A feedback signal is used to dither the temperature of a frequency doubled crystal so as to minimize the noise in the frequency doubled output signal.

Abstract: The present invention provides an auto-power control (APC) circuit and a method to stabilize the extinction ratio of an optical output from a laser diode (LD) in an optical transmitter. The APC circuit according to the invention includes two feedback loops for the modulation IM and the bias current IB each having variable loop gain. The extinction ratio of the optical output from the LD is kept constant by setting the ratio of the loop gains of respective APC circuits to be ER?1.

Abstract: The present invention provides an external resonator-type wavelength tunable laser device that can properly fulfill a wavelength tuning function even with the use of a planar wavelength tunable reflector involving a considerable level of residual reflection. The external resonator-type wavelength tunable laser device includes a planar reflection structure enabling a reflection spectral peak wavelength to be varied and a semiconductor element as a semiconductor gain medium. The semiconductor gain medium is composed of a multiple quantum well in which product ?·L of optical confinement constant ? and semiconductor gain medium length L (?m) of a gain layer is at least 25 ?m and at most 40 ?m and in which gain peak wavelength ?0 (nm) observed during carrier injected with a maximum modal gain equal to an internal loss of the semiconductor gain medium is larger than ?3·?R/2+(?c+35) and smaller than (?(?·L)/7+8)·?R+(?(?·L)+?c+45).

Abstract: A pulsed laser comprises an oscillator and amplifier. An attenuator and/or pre-compressor may be disposed between the oscillator and amplifier to improve performance and possibly the quality of pulses output from the laser. Such pre-compression may be implemented with spectral filters and/or dispersive elements between the oscillator and amplifier. The pulsed laser may have a modular design comprising modular devices that may have Telcordia-graded quality and reliability. Fiber pigtails extending from the device modules can be spliced together to form laser system. In one embodiment, a laser system operating at approximately 1050 nm comprises an oscillator having a spectral bandwidth of approximately 19 nm. This oscillator signal can be manipulated to generate a pulse having a width below approximately 90 fs.

Abstract: A semiconductor light source with optical feedback includes a vertical member extending upward from an upper horizontal surface of a header parallel to a vertical beam projected from a semiconductor light-emitting element mounted on the horizontal surface of the header wherein the vertical member supports a light-sensing element for receiving light reflected transversely from the vertical beam by a beam splitter supported by the vertical member. The vertical beam passing through the beam splitter passes through a window or filter in a cap mounted on the header and covering the light-emitting element, the light-sensing element, the beam splitter, and the vertical member. Substantially all of the transversely reflected light impinges on the light-sensing element and can be used to control the power to the light-emitting element. A simple lens can by used to collimate the beam. Interior portions of the unit are formed from light absorbing materials such as black ceramic, black plastic, anodized aluminum, etc.

Abstract: A wavelength tunable laser module for DWDM is used, in which a single electroabsorption modulator integrated laser is mounted and an oscillation wavelength is made tunable by temperature control. Driving conditions of a laser and a modulator are determined such that they have approximately the same modulation and transmission characteristics in a temperature control range. Such an electroabsorption modulator integrated laser is used and the driving conditions are incorporated, thereby a small, inexpensive wavelength tunable optical transmitter can be provided.

Abstract: A driver laser for EUV light source apparatus which driver laser simultaneously achieves short-pulsing and multi-line oscillation. The driver laser includes: a short-pulse multi-line oscillated CO2 laser oscillator having a device that shortens width of pulses included in a laser beam to be output and a device that suppresses amplitude of an oscillation spectrum exhibiting an energy peak value; and at least one amplifier that inputs the laser beam output from the short-pulse multi-line oscillated CO2 laser oscillator and amplifies the input laser beam to output the amplified laser beam.

Abstract: A drive signal for driving a semiconductor laser is generated on the basis of an image signal inputted in synchronism with a pixel clock. A bias signal to the semiconductor laser is generated at a timing earlier than the drive signal by a predetermined time. The bias signal is disabled in synchronism with the leading edge of the drive signal.

Abstract: The teachings presented herein disclose a method and apparatus for controlling the optical power of a laser in a passive optical network transmitter that outputs a modulated optical signal responsive to a modulated input signal. In one or more embodiments, such a control method comprises detecting the peak amplitude of the modulated input signal, and setting the DC bias level of the laser as a function of the detected peak amplitude. These teachings may be implemented, for example, by a laser control circuit in the transceiver module of an optical network unit (“ONU”). Such an ONU may be advantageously used in a hybrid coaxial cable-optical fiber network, such as used in DPONs which interface cable system subscriber equipment to cable system head-end equipment.

Abstract: An optical module is configured with a combination of a single-mode oscillating light source and an optical filter. In this optical module, the single-mode oscillating light source outputs a single-mode, frequency-modulated signal. Further, the optical filter converts the frequency modulation to an amplitude modulation. And, the single-mode oscillating light source and the optical filter are packaged without active alignment on the same substrate. Accordingly, it is possible to realize an optical module in a simple and low-cost configuration by packaging the single-mode oscillating light source and the optical filter by passive alignment, without active alignment, on the same substrate, and by using a simple optical filter such as a waveguide ring resonator, which converts a frequency modulation to an amplitude modulation.

Abstract: An apparatus/method may comprise a line narrowed pulsed lithography laser light source which may comprise: a seed pulse providing laser system which may comprise: a first pulsed seed laser producing seed pulses at a rate of X kHz; a second pulsed seed laser producing seed pulses at a rate of X kHz; an amplification system which may comprise: a first amplifier gain system which may comprise a first and a second pulsed gas discharge amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the first seed laser; a second amplifier gain system which may comprise a first and a second pulsed amplifier gain medium, each with a nominal center wavelength in the UV range, and each operating at ½ X kHz on output pulses from the second seed laser.

Abstract: The present invention relates to an optical amplifier module, or the like, having a structure for enabling effective suppression of photodarkening and efficient optical amplification. The optical amplifier module comprises a first optical amplification waveguide which is comprised of a phosphate glass as a main component and includes a ytterbium-doped first optical waveguide region, a second optical amplification waveguide which is optically coupled to the first optical amplification waveguide and includes a ytterbium-doped second optical waveguide region which is co-doped with aluminum, and pumping light source units which supply pumping light respectively to the first optical amplification waveguide and the second optical amplification waveguide. The light to be amplified, having inputted to the first optical amplification waveguide, is amplified only once by means of the pumping light, in each of the first optical amplification waveguide and the second optical amplification waveguide.

Abstract: The invention discloses an optical transmission module with digital adjustment and method thereof. The module includes a laser (21), a laser driver (22), an automatic power adjustment circuit (23), an automatic temperature adjustment circuit (24), a digital adjustment circuit (25) and a memory (26). The digital adjustment circuit, consisted of a digital-to-analog converter or a digital adjustment potentiometer, receives a digital adjustment signal and outputs, respectively, a extinction ratio adjustment signal and a cross point adjustment signal to the laser driver, an optical power adjustment signal to the automatic power adjustment circuit and an optical wavelength adjustment signal to the automatic temperature adjustment circuit. The memory stores data, using for on-line adjustment of the optical transmission module, at least including parameters of said optical transmission module and said laser emitting optical power parameters, to be reported upward.

Abstract: The present invention provides a kind of ultra-wide band wireless system, which changes the previous electronic structure for ultra-wide band pulse generator, and uses light to generate pulse signal, transformed by microwave differentiator to Gaussian monocycle pulse transmission signal, the derived pulse signal can provide several GHz bandwidth to transmit fast speed information, and further complete the new ultra-wide band wireless system. It reduces the complexity of electronic system and enhances output signal quality by means of light property, with considerable leading advantage. And the signal generated by this system has broader band and no infringe property, its 10 dB band falls within the range prescribed by the Federal Communication Committee of United States (FCC), successfully realizing the ultra wide band fiberoptic wireless collection network system, and further attaining the goal of seamless communication collection.

Abstract: In a laser power control apparatus for controlling a laser power of a combination drive, first laser light Lc applied onto a first optical disk and second laser light Ld applied onto a second optical disk is collected by one photodetector 8.

Abstract: Apparatus and method for generating controlled-linewidth laser-seed-signals for high-powered fiber-laser amplifier systems. In some embodiments, the natural chirp (frequency change of laser light over a short start-up time) of a DBR laser diode when driven by pulsed current is used to broaden the linewidth of the laser output, while adjusting the peak current and/or the pulse duration to obtain the desired linewidth.

Abstract: In the laser system of the present invention, an acoustic grating (AG) established in an SBS cell by an initial laser pulse is forced into oscillation from noise. Since the process is nonlinear, SBS Phase Conjugation does not take place until a specific level is achieved based on several factors such as the physical conditions and the SBS media. The invention segments the initial laser pulse with a zonal lenslet array that produces a set of beams that have their foci distribute in space. By coupling this segmented lenslet array with a master lens, the separation of the foci from each other can be controlled. At a large separation distance each foci independently produces an associated AG. As each AG forms from a local noise source the coherence between the segmented beams has been lost. However, the master lens controls the entire focal envelope and hence the separation distance between the foci. Increasing the power of the master lens causes the separation between the foci to decrease.