Abstract: This invention provides a method for commissioning and upgrading an optical ring network using its internal amplifiers as Automatic Spontaneous Emission sources of light that are used in making measurements. A modular segmented approach is adopted and the network is commissioned segment by segment. A flexible method is used for upgrading a commissioned network by adding or deleting a node or changing the internal configuration of a node. The method uses techniques for the correction of the Optical Signal to Noise Ratio induced error as well as the Spectral Filtering Error during the loss computation required for adjusting the gains of the amplifiers at each network node to an appropriate value. Since the method does not require an external laser source that needs to be moved manually from node to node it greatly reduces the commissioning time. Since it uses only the components of the network itself and does not deploy any additional device it also leads to a significant saving in cost.

Abstract: A flexible optical waveguide film comprises: two waveguide cores; and a clad surrounding the two waveguide core, wherein a light entrance/exit part is disposed at one end of each of the two waveguide cores, the waveguide film having an optical path converting part comprising an air void located inside the waveguide film, and a light entrance/exit end face of the light entrance/exit part is a plane surface facing an optical path converting surface of the optical path converting part, the optical path converting surface being an interface defining the air void.

Abstract: An ignition device for an internal combustion engine, in particular of a motor vehicle, includes at least one pump light source, which provides a pump light. Furthermore, a laser device is provided, which is able to generate a laser light for beaming into a combustion chamber. A waveguide device transmits the pump light from the pump light source to the laser device. The laser device includes at least one refraction device, for example, a lens, which refracts the pump light and is in one piece therewith.

Abstract: A medical device includes an insertable portion capable of being inserted into an orifice associated with a body of a patient. The insertable portion comprising an automated head unit capable of being manipulated in at least two axes of motion based at least in part on one or more control signals. The medical device further includes one or more controllers coupled to the automated head unit. In one particular embodiment, the one or more controllers generate the one or more control signals based at least in part on an input signal.

Abstract: A Self-adapting feed forward control apparatus in an optical amplifier includes a feed forward controller for collecting target output power (Pout) and controlling drive current of a pump laser in the optical amplifier; a feedback controller for calculating target output power (Pt) and collecting actual output power (Pout), calculating deviation between (Pt) and (Pout), and controlling drive current of the pump laser; and a parameter estimator for collecting power target, output power and summation of output signal of the feed forward controller and feedback controller, and estimating the feed forward parameter and updating the parameter of the feed forward controller. The apparatus can automatically correct the feed forward control parameters according to the variation of EDFA parameters due to environmental condition changes or device aging.

Abstract: The present invention includes a laser amplifier and a method of making the same. The laser amplifier of the present invention includes a gain medium layer having a first index of refraction, and a coupling layer optically coupled to the gain medium. In the various embodiments described herein, the coupling layer can have a second index of refraction less than the first index of refraction. The laser amplifier described herein can also include an evanescent layer disposed between the gain medium and the coupling layer. The evanescent layer can have a third index of refraction less than the second index of refraction. The laser amplifier provides high power, efficient laser resonance through frustrated total internal reflection and total internal reflection while simultaneously providing for the minimization of waste heat in the gain medium layer.

Abstract: An optical amplifier apparatus capable of dealing with different wavelength bands and capable of outputting an amplified light with reduced noise for any one of the wavelength bands. In a case of amplifying a light of C-band, terminals (51,52) of an optical switch (50) are connected to each other. An incident light is amplified by a first front-end optical fiber amplifier (12) and a first back-end optical fiber amplifier (18). The amplified light passes via the terminals (51,52) and through a back-end WDM coupler (36) and goes out of the optical amplifier apparatus (1). In a case of amplifying a light of L-band, terminals (51,54) of the optical switch (50) are connected to each other, while terminals (52,53) thereof are connected to each other.

Abstract: An optical pulse position modulation receiver relying on the gain dynamics in a semiconductor optical amplifier (SOA). Optical PPM signal pulses and periodic optical clock pulses at a different frequency and/or polarization than the signal pulses are coupled into an SOA. Due to the high optical power of the clock pulses, the SOA gain will drop to a small value after each clock pulse. The SOA will then amplify each signal pulse that follows the clock pulse, and the gain will depend on the delay between the signal pulse and the preceding optical clock pulse. The optical output of the SOA can then be converted to an electrical signal by a photodetector.

Abstract: Optical power monitoring capable of achieving a wide dynamic range and high-speed response is realized. An optical power monitoring circuit includes: a first amplifier (TIA 2) that amplifies an input current from a light-receiving element (PD 1) with a variable gain to convert the current into a voltage signal; a second amplifier (LIM 3) that amplifies the output of the first amplifier to convert the output into a main signal output; a third amplifier (AMP 4) that amplifies the output of the first amplifier with a variable gain to convert the output into a monitor output; and a gain variable means (amplifier comparator 5) for changing the gain of the first amplifier and gain of the third amplifier depending on the output of the first amplifier.

Abstract: A rotary disk module, having a rotary disk is interposed between a pair of heat sinks each spaced from the rotary disk by a gap. A motor is installed for driving the rotary disk to rotate. The gaps are filled with cooling medium such as helium, water or liquid nitrogen to remove the heat generated in the rotary disk by conduction, convection or evaporation. The rotary disk may be fabricated from various materials depending on the intended applications of the module, and the heat sink surfaces are preferably fabricated from materials with higher thermal conductivity. The rotation of the rotary disk allows the regions on which an optical pump radiation is delivered to be separated from the regions from which an optical radiation is extracted. In addition to improved heat dissipation effect, the rotation of the optical disk allows multiple directions of pump energy or multiple sources of pump energies and/or multiple beams of optical radiation to be applied and extracted simultaneously.

Abstract: An optical amplifier is included within a fiber optic transmission system for driving a fiber optic towed decoy system. The optical amplifier boosts the optical power of a laser on board the driving system and compensates for link loss within the driving system and link loss associated with a blind connection between the driving system and the towed decoy. The optical amplifier may be an erbium doped fiber amplifier and may be run in a saturation mode. The result is a towed decoy system capable of operating more consistently across a range of platforms and in some cases less stringent gain requirements on towed decoy components.

Abstract: A nonlinear optical system comprises a metallic film having a first side and a second side. The nonlinear optical system further comprises a regular array of slits in the metallic film. The slits connect the first and second sides of the metallic film. The array is configured to selectively transmit through the metallic film light having frequencies of a selected frequency band. The nonlinear optical system still further comprises a nonlinear optical material situated within the slit.

Abstract: The invention describes techniques for the control of the spatial as well as spectral beam quality of multi-mode fiber amplification of high peak power pulses as well as using such a configuration to replace the present diode-pumped, Neodynium based sources. Perfect spatial beam-quality can be ensured by exciting the fundamental mode in the multi-mode fibers with appropriate mode-matching optics and techniques. The loss of spatial beam-quality in the multi-mode fibers along the fiber length can be minimized by using multi-mode fibers with large cladding diameters. Near diffraction-limited coherent multi-mode amplifiers can be conveniently cladding pumped, allowing for the generation of high average power. Moreover, the polarization state in the multi-mode fiber amplifiers can be preserved by implementing multi-mode fibers with stress producing regions or elliptical fiber cores. These lasers find application as a general replacement of Nd: based lasers, especially Nd:YAG lasers.

Abstract: A chirped pulse amplifier (CPA) system having a mode-locked laser and a high-speed pulse selector, wherein the pulse selector modulates output pulses based upon an applied modulation voltage. A pulse selector may be an integrated electro-optic modulator, for example a LiNbO3 modulator, or an electro-absorption modulator. Difficulties related to free-space alignment and operational stability of some prior designs are reduced or eliminated. Fiber coupling generally simplifies beam delivery and alignment. Some embodiments include an erbium fiber (or erbium-ytterbium) based CPA system operating at a wavelength of approximately 1550 nanometers. Similar performance can be obtained at other wavelengths, for example a 1.06 .micrometer Yb-doped fiber system. Moreover, high amplification and peak intensity at the output may be achieved while avoiding non-linear effects in the pulse selector, thereby providing for high intensity picosecond or femtosecond operation.

Abstract: Systems and devices for use as optical transceivers and amplifiers in optical networks. An optical transceiver/amplifier has two optical signal circulators, each of which receives one incoming signal and transmits one outgoing optical signal. Each circulator combines its incoming and outgoing signals on to a bidirectional optical connection internal to the transceiver amplifier. Between the two circulators are a pump laser, an optical coupler to couple the pump laser's power into the bidirectional connection, and an amplifying medium for amplifying the bidirectional signal's internal to the transceiver amplifier. The amplifying medium may be an Erbium doped fiber which would amplify any optical signal passing through it. In one embodiment, the transceiver amplifier is in a self-contained package that is pluggable into existing equipment using pre-existing ports and interfaces.

Abstract: Disclosed is an optical transmission device with a simple configuration that can attenuate an input optical power only when it is necessary so that it falls within a predetermined range, and can suppress insertion loss when it is unnecessary. A variable optical attenuator is configured pluggable. A pluggable variable optical attenuator is equipped with an optical connector that is an interface of an optical signal and an electrical signal connector for receiving an electrical signal that specifies the amount of control used for feedback-controlling the attenuation, and controls the attenuation depending on the input optical power of the optical transmission board. Moreover, an optical through that has the same shape as the variable optical attenuator being configured pluggable and that is configured pluggable is prepared.

Abstract: A device is described herein which may comprise an oscillator having an oscillator cavity length, Lo, and defining an oscillator path; and a multi-pass optical amplifier coupled with the oscillator to establish a combined optical cavity including the oscillator path, the combined cavity having a length, Lcombined, where Lcombined=(N+x)*Lo, where “N” is an integer and “x” is a number between 0.4 and 0.6.

Abstract: In an optical amplification characteristics simulation apparatus according to the present invention, using spectrums of a signal light input to an optical amplifier and a characteristic parameter for amplification medium, gain wavelength characteristics of the amplification medium are calculated. A calculating formula for the above has a parameter corresponding to a gain fluctuation portion due to a gain spectral hole burning (GSHB) phenomenon, and this parameter is defined by a function obtained by modeling a physical phenomenon in which a population inversion rate is reduced due to the GSHB, based on that electron occupation numbers in each Stark level on the end level side are increased. Then, based on the calculated gain wavelength characteristics, the output power of the signal light is obtained, to thereby perform the optical amplification characteristics simulation on the optical amplifier.

Abstract: [Problems] To accommodate a plurality of optical semiconductor elements in one package with their optical axes aligned highly precisely. [Means for Solving the Problems] An optical transmission module includes an optical transmission unit, a carrier to become a base, a semiconductor optical amplification element mounted on the carrier through a first sub-carrier, first and second lenses fixed on the carrier through first and second lens holders, an element supporting member and an optical isolator fixed on the carrier, a third lens holder supported by the element supporting member, a third lens and a small carrier individually fixed in the third lens holder, and a semiconductor laser element mounted on the small carrier through a second sub-carrier.

Abstract: A laser active optronic system has an emission channel for the emission by an emission source of a laser beam which illuminates a target, and a receiving channel for receiving the wave backscattered by the target. An optical switching device is positioned in the receiving channel to receive the backscattered wave and has an optical gain medium and pumping means for pumping the gain medium. The gain medium is absorbent at the wavelength of the laser and becomes substantially transparent when it is pumped to allow the switching device to be actuated in the on mode or off mode respectively. A control unit for controlling the pumping means, allows the switching device to be actuated in the on mode in at least one temporal window of predetermined duration, triggered at a predetermined instant after the start of emission of the illuminating laser beam.

Abstract: An imaging and display system provides helicopter pilots with an unobstructed display of a landing area in a brownout or whiteout condition by capturing a high resolution image of the landing area prior to obscuration. Using inertial navigation information from the aircraft or an independent system, the system transforms the image to a desired viewpoint and overlays a representation of the helicopter's current position relative to the landing area. The system thus greatly improves orientation and situational awareness, permitting safe and effective operation under zero visibility brownout conditions.

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 laser light source includes a light source section for outputting pulse laser light ?1, ?2 with a mutually identical repetition frequency, an optical amplification section for amplifying and outputting the pulse laser light ?1, ?2 output from the above light source section by means of a common optical amplification medium, an optical demultiplexing section for mutually demultiplexing pulse laser light ?1, ?2, an optical multiplexing section for multiplexing and outputting the pulse laser light ?1, ?2 demultiplexed in the above optical demultiplexing section, and an optical path length difference setting section for adjusting an optical path length difference between the pulse laser light ?1, ?2 in between the optical demultiplexing section and the optical multiplexing section.

Abstract: An operational optical transceiver configured to preserve a portion of volatile memory during a warm reboot process. The optical transceiver includes a persistent memory, a processor, and a system memory. The system memory includes a preserved memory space. The optical transceiver loads microcode from the persistent memory to the system memory without writing into the preserved memory space. The processor processes the microcode and writes certain information into the preserved memory space that will be preserved during a warm reboot. The optical transceiver may then initiate a warm reboot and load microcode from the persistent memory to the system memory that overwrites the existing microcode. However, the information written in the preserved memory space is not overwritten by the microcode loaded from the persistent memory. In this way, a portion of the information contained in the system memory prior to the warm reboot is preserved.

Abstract: An optical amplifier module contains at least one optical amplifier. The module includes an internal housing having an outer dimension substantially equal to an outer dimension of an internal fiber splice housing of an undersea optical fiber cable joint. The internal housing includes a pair of opposing end faces each having a retaining element for retaining the internal housing within an outer housing of the undersea optical fiber cable joint. The internal housing also includes a sidewall interconnecting the opposing end faces, which extends between the opposing end faces in a longitudinal direction. The sidewall includes a receptacle portion having a plurality of thru-holes each being sized to receive a passive optical component employed in an optical amplifier.

Abstract: A semiconductor laser module has a semiconductor laser device; a package for housing the semiconductor laser device; a PBC fixed in the package for polarization-synthesizing two laser beams output from the semiconductor laser device; a depolarizing element fixed in the package for depolarizing a synthesizing light output from the PBC; and an optical fiber for receiving a light output from the depolarizing element.

Abstract: By writing non-linear chirp into fiber Bragg gratings, greater control over dispersion compensation in chirped pulse amplification (CPA) systems is obtained, such that, for example, the dispersion profile of the fiber Bragg grating and a bulk compressor may be matched. An iterative method of writing the fiber grating can reduce the group delay ripple to very low levels; and adaptive control of the fiber grating dispersion profile can further reduce these levels, while in addition offering greater acceptable yield in the manufacture of such gratings. Fiber Bragg gratings may be designed so as to provide customized pulse shapes optimized for various end uses, such as micromachining, for example, and may also be used to counteract gain-narrowing in a downstream amplifier.

Abstract: A laser light source is disclosed having a laser oscillator producing an output beam; a first amplifier amplifying the output beam to produce a first amplified beam, and a second amplifier amplifying the first amplified beam to produce a second amplified beam. For the source, the first amplifier may have a gain medium characterized by a saturation energy (Es, 1) and a small signal gain (go, 1); and the second amplifier may have a gain medium characterized by a saturation energy (Es, 2) and a small signal gain (go, 2), with (go, 1)>(go, 2) and (Es, 2)>(Es, 1). In another aspect, a laser oscillator of a laser light source may be a cavity dumped laser oscillator, e.g. a mode-locked laser oscillator, q-switched laser oscillator and may further comprising a temporal pulse stretcher.

Abstract: An electronic circuit for controlling a laser system consisting of a pulse source and high power fiber amplifier is disclosed. The circuit is used to control the gain of the high power fiber amplifier system so that the amplified output pulses have predetermined pulse energy as the pulse width and repetition rate of the oscillator are varied. This includes keeping the pulse energy constant when the pulse train is turned on. The circuitry is also used to control the temperature of the high power fiber amplifier pump diode such that the wavelength of the pump diode is held at the optimum absorption wavelength of the fiber amplifier as the diode current is varied. The circuitry also provides a means of protecting the high power fiber amplifier from damage due to a loss of signal from the pulse source or from a pulse-source signal of insufficient injection energy.

Abstract: An optical amplification apparatus includes an optical amplification medium which has an input end and an output end, and amplifies an optical signal by a predetermined amplification rate; a first light source for launching excited light which excites the optical amplification medium; an isolator connected to the output end of the optical amplification medium; and a second light source for launching idle light which has a predetermined wavelength and is launched into the optical amplification medium from a point between the optical amplification medium and the isolator. The optical amplification medium, the first light source, the isolator, and the second light source are contained in the package of the optical amplification apparatus. The apparatus may further include a set of an optical absorption member for absorbing the idle light and an circulator connected to the input end of the optical amplification medium, or an input-side isolator connected to the input end of the optical amplification medium.

Abstract: An exemplary illumination apparatus for use in a projection system includes a number of solid-state light sources and first non-imaging collection optics, a power coupler, an optical amplifier, and a second non-imaging collection optic. The solid-state light sources are configured to generate light of a predetermined wavelength. Each first non-imaging collection optic is configured to collect and transmit light from a respective solid-state light source to the power coupler. The power coupler is configured to combine light from the solid-state light sources. The optical amplifier is configured to amplify the combined light. The second non-imaging collection optic is configured to collect the amplified light to provide illumination.

Abstract: The present invention purposes to provide a THz-wave generator capable of generating a THz-wave stably and efficiently, and particularly, to provide the THz-wave generator which is stable against a frequency shift of a laser source and which can easily vary the frequency of the THz-wave. A THz-wave generator, for inputting a laser beam from a light source unit A including a laser source to a THz-wave generating element D, and generating a THz-wave (fT) from the THz-wave generating element, wherein a light circulating unit including an SSB optical modulator, and wavelength selecting means C are disposed between the laser source A and the THz-wave generating element D, the laser beam is guided into the light circulating unit, a specific wavelength lightwave is selected out of lightwaves having a plurality of wavelengths generated in the light circulating unit by the wavelength selecting means, and the specific wavelength (f0, fn) lightwave is input to the THz-wave generating element.

Abstract: A method for generating a linear single-polarization output beam comprises providing an optically active linearly birefringent and linearly dichroic fiber for propagating light and having a single polarization wavelength range and a gain bandwidth; optically pumping the optically active linearly birefringent and linearly dichroic fiber for obtaining fluorescence within the gain bandwidth; and aligning the single-polarization wavelength range to overlap a desired spectral region of the gain profile.

Abstract: There is provided a parabolic pulse amplifier for amplifying a pulse light signal. The amplifier comprises an ytterbium-doped amplification waveguide pumped using a pump source with a pump central wavelength substantially offset from the absorption transition peak wavelength. The pump wavelength is selected such that the absorption coefficient of pump light and the gain coefficient of the signal are substantially equal in the amplification waveguide such that the amplification gain is distributed substantially uniformly along the amplification waveguide.

Abstract: An undersea optical repeater is provided. The repeater includes a pressure vessel for use in an undersea environment. The pressure vessel includes a pressure housing and at least two cable reeving elements disposed on opposing ends of the pressure housing for respectively receiving ends of optical cables that each include an electrical conductor therein. The cable receiving elements are adapted to be in electrical contact with the respective electrical conductors in the optical cables. At least one optical amplifier is located in the pressure vessel. The optical amplifier includes at least one electrical component adapted to receive electrical power from the electrical conductors in the optical cables. The pressure housing includes a dielectric layer having sufficient dielectric properties for electrically isolating the cable receiving elements from one another to provide a voltage thereacross.

Abstract: A method and apparatus for dispersion compensation which provides a specified, well-controlled, wavelength-dependent optical path length in a laser or other optical system. A reflection grism-like device with an angled output interface is designed to simultaneously provide negative GVD and negative TOD, and therefore can be used to compensate for material dispersion. These gratings are very efficient due to their near-Littrow configuration and can be used over a broad spectral range, which is particularly useful in ultra-short-pulse applications.

Abstract: An all-fiber chirped pulse amplification (CPA) system and method is provided that utilizes a hollow core photonic bandgap fiber as a pulse compressor and a dispersion compensating optical fiber as a pulse stretcher that are matched with respect to both the amount and slope of dispersion to avoid peak power-limiting pulse distortion. The CPA system includes a rare earth ion-doped optical fiber amplifier having an input and an output that amplifies optical pulses having a center wavelength of ?c, a pulse compressing length L1 of hollow core photonic bandgap fiber having a dispersion value D1 and a dispersion slope S1 that varies over a wavelength ? of the pulses that is optically connected to the output of the fiber amplifier and having a k-parameter defined by a ratio of D1 over the slope of the function D1(?) that is larger than about 50, and a pulse stretching length L2 of dispersion compensating optical fiber connected to the input of the fiber amplifier having a dispersion value D2 and dispersion slope S2.

Abstract: System for converting relatively long pulses from rep-rate variable ultrafast optical sources to shorter, high-energy pulses suitable for sources in high-energy ultrafast lasers. Fibers with positive group velocity dispersion (GVD) and self phase modulation are advantageously employed with the optical sources. These systems take advantage of the need for higher pulse energies at lower repetition rates so that such sources can be cost effective.

Abstract: The specification describes an optical fiber device wherein a LOM is converted to an HOM prior to entering the gain section. The gain section is a few mode fiber that supports the HOM. The output from the gain section, i.e. the HOM, may be utilized as is, or converted back to the LOM. With suitable design of the few mode fiber in the gain section of the device, the effective area, Aeff, may be greater than 1600 ?m2. The large mode separation in the gain section reduces mode coupling, allowing greater design freedom and reducing the bend sensitivity of the optical fiber.

Abstract: A method of and device for generating an amplified optical signal directly in an optical fiber by way of phase-sensitive amplification based on one or more four-wave mixing (FWM) processes. In one embodiment, an input signal and two pump waves are applied to a highly nonlinear fiber (HNLF). The input signal is amplified in the HNLF due to energy transfer from the pump waves to the input signal via a degenerate phase-conjugation (PC) process. In another embodiment, an input signal and first and second pump waves are applied to a first HNLF to generate, via a Bragg scattering (BS) process, an idler signal corresponding to the input signal. The second pump wave is then filtered out and the first pump wave, a third pump wave, and the input and idler signals are applied to a second HNLF, where they interact via a non-degenerate PC process to produce an amplified output signal.

Abstract: An apparatus is provided comprising a dual optical amplifier. The two optical amplifiers are integrated, in that they share at a set of optical, electrical, or opto-electrical components. The two optical amplifiers may share a pump laser. Alternatively, the optical amplifiers may share photo-detectors. Methods of controlling the signal strength of output signals are also provided. A chip-based integrated optical dual amplifier, using Erbium-Doped Waveguides, is also provided.

Abstract: An arrangement has a WDT (Wavelength-Dependent Tap) coupled in an OCS (Optical Communication System) and an OPM (Optical Performance Monitoring) function coupled to the WDT. The WDT is adapted to receive from the OCS an input optical signal having noise and channels at respective channel wavelengths. The WDT couples to an output some of the input optical signal at the channel wavelengths and most of a noise power at wavelengths between the channel wavelengths, and couples a remaining portion of the input optical signal back into the optical communication system. The optical performance monitoring function determines a power characteristic of the input optical signal as a function of a power from the output. The power characteristic may be an OSNR (Optical Signal-to-Noise Ratio) determined as a function of a signal power and a noise power of the output optical signal.

Abstract: A MEMS-tunable semiconductor optical amplifier (SOA). A device in accordance with the present invention comprises a substrate, a first mirror, coupled to the substrate, a second mirror, an active region, coupled between the first and second mirror, and a microelectromechanical actuator, coupled to the second mirror, wherein a voltage is applied to the microelectromechanical actuator to tune the SOA.

Abstract: An optical signal and pump light are input to a nonlinear optical medium. In the nonlinear optical medium, the optical signal is amplified with a nonlinear effect caused by the pump light. A monitor circuit monitors parametric gain in the nonlinear optical medium. A first power controller increases input power of the optical signal so that the gain reaches saturation. A second power controller controls input power of the pump light so as to obtain a desired gain.

Abstract: According to an aspect of an embodiment, an apparatus includes an optical branching unit for branching an input signal light in four directions, a polarization component extraction unit extracting four polarization components having mutually different polarization parameters from lights branched in four directions by the optical branching unit, and a determination unit determining input/non-input of the signal light based on the four polarization components extracted by the polarization component extraction unit.

Abstract: An optical transmission system includes an optical nonlinear element having nonlinear input/output characteristics, a power detector detecting a power of a specific frequency component related to an optical signal reproduced by the optical nonlinear element, and a variable amplifier amplifying or attenuating the optical signal inputted to the optical nonlinear element. Evaluation of an output waveform is performed based on the power of the specific frequency component detected by the power detector, and a gain of the variable amplifier is properly controlled, so that an input power of the optical signal inputted to the optical nonlinear element can be easily set such that a good output waveform can be obtained without directly measuring the inputted or outputted optical signal.

Abstract: A spatially-fed high-power amplifier comprises one or more shaped reflectors to reflect an initial wavefront, and an active array amplifier to amplify the reflected wavefront to generate a high-power planar wavefront. The shaped reflectors provide the reflected wavefront with substantially uniform amplitude when incident on the active array amplifier. The initial wavefront may be a substantially spherical wavefront, and the shaped reflectors may compensate for any amplitude taper of the initial wavefront to provide the reflected wavefront with substantially uniform amplitude components for incident on the active array amplifier. In some embodiments, the shaped reflectors may also contour the illumination to fit the shape of the active array amplifier to help minimize spillover.

Abstract: A fiber Chirped Pulse Amplification (CPA) laser system includes a fiber mode-locking oscillator for generating a laser for projecting to a fiber stretcher for stretching a pulse width of the laser wherein the stretcher further comprising a self-phase modulation (SPM) assisted photonics crystal fiber (PCF) single mode (SM) fiber stretcher. The fiber CPA laser system further includes a multistage amplifier for amplifying the laser and a high-order dispersion-compensating compressor for compensating high order dispersions and compressing the pulse width of the laser.

Abstract: A chirped pulse amplifier (CPA) system having a mode-locked laser and a high-speed pulse selector, wherein the pulse selector modulates output pulses based upon an applied modulation voltage. A pulse selector may be an integrated electro-optic modulator, for example a LiNbO3 modulator, or an electro-absorption modulator. Difficulties related to free-space alignment and operational stability of some prior designs are reduced or eliminated. Fiber coupling generally simplifies beam delivery and alignment. Some embodiments include an erbium fiber (or erbium-ytterbium) based CPA system operating at a wavelength of approximately 1550 nanometers. Similar performance can be obtained at other wavelengths, for example a 1.06 .micrometer Yb-doped fiber system. Moreever, high amplification and peak intensity at the output may be achieved while avoiding non-linear effects in the pulse selector, thereby providing for high intensity picosecond or femtosecond operation.

Abstract: Techniques for designing optical devices with passive components for erbium and other doped fiber amplifiers are disclosed. In one aspect, all passive components needed to construct optical amplifiers of both single and multiple-stage forward or backward pumps are integrated without extensively using optical fiber splicing joints. One of the features is to use free-space optics for inter-function cascades among various necessary functions, such as one or more tap couplings, WDM filtering to multiplex (Mux) or de-multiplex (Demux) pump and signal lights, gain-flattening, pump isolation and even performing Mux and Demux of different polarizations.