Abstract: In one aspect, a signal processing system includes a processor, an I/O device operatively associated with the processor, and a memory device bearing instructions configured to cause the processor to obtain a representation of signal data over a data domain and position a sliding-window over a portion of the signal data, such portion corresponding to a sliding-window domain, to analyze the signal data within the sliding-window domain to detect the presence of a signature multiplet and, based on the analysis of the data, to estimate the pedestal of the signal data within the sliding-window domain.

Abstract: An optical amplifier system includes a diode pump array including a plurality of semiconductor diode laser bars disposed in an array configuration and characterized by a periodic distance between adjacent semiconductor diode laser bars. The periodic distance is measured in a first direction perpendicular to each of the plurality of semiconductor diode laser bars. The diode pump array provides a pump output propagating along an optical path and characterized by a first intensity profile measured as a function of the first direction and having a variation greater than 10%. The optical amplifier system also includes a diffractive optic disposed along the optical path. The diffractive optic includes a photo-thermo-refractive glass member. The optical amplifier system further includes an amplifier slab having an input face and position along the optical path and separated from the diffractive optic by a predetermined distance.

Abstract: A fiber laser amplifier system including a master oscillator that generates a signal beam. A splitter splits the signal beam into a plurality of fiber beams where a separate fiber beam is sent to a fiber amplifier for amplifying the fiber beam. A tapered fiber bundle couples all of the output ends of all of the fiber amplifiers into a combined fiber providing a combined output beam. An end cap is optically coupled to an output end of the tapered fiber bundle to expand the output beam.

Abstract: Systems and methods for coherent beam combination of lasers are provided. In one embodiment, a method for coherent beam combination is provided. The method comprises providing a plurality of secondary laser signals from a primary laser signal, amplifying the plurality of secondary signals along respective amplifier arms to provide a plurality of amplified output signals, providing a frequency-shifted reference beam from the primary laser signal, generating a plurality of optically heterodyne detected (OHD) beat signals based on combining respective amplified output signals of the plurality of amplified output signals with the frequency-shifted reference beam, and adjusting path lengths of respective amplifier arms based on respective amplitudes of the plurality of OHD beat signals to control the path length of respective amplifier arms to within a coherence length of the primary laser signal.

Abstract: A photon engine and variations thereof and methods of operating the photon engines, the photon engines comprising a primary prism and a secondary prism, the method and apparatus repeatedly imparting linear momentum to multiple reflective surfaces of the photon engine communicating with an energy system.

Abstract: An optical pumping device is provided in which a multi-core fiber obtained by bundling up a plurality of optical fibers, which are input ports, and a double clad fiber for optical pumping are spliced through a bridge fiber composed of a double clad fiber having a tapered shape. Accordingly, it is possible to efficiently couple signal light and pumping light to the double clad fiber for optical pumping.

Abstract: A method and system whereby a narrow linewidth coherent laser source when transmitted as a plurality of output signals and subsequently detected at a distance appears to produce the uniform illumination characteristics of an incoherent source thereby suppressing laser speckle and environmentally induced scintillation effects. A master oscillator source is split into N signals, each of which is independently phase modulated by frequencies designed to minimize a derived apparent incoherence factor. The signals are then either directed to an object to be illuminated so that they overlap at the object or first recombined and directed to the object.

Abstract: In a THz wave generator for generating a THz wave from a THz wave generating element by inputting a plurality of laser beams having different wavelengths to the THz wave generating element, all of the plurality of laser beams are formed into a pulse beam by the pulse generator and the pulse beam is amplified by a single optical amplifier E to which the laser beams are inputted with polarization planes of the laser beams being controlled, and then the pulse beam is inputted to the THz wave generating element F. Preferably, the plurality of laser beams having different wavelengths are generated by inputting single wavelength beam to a multi wavelength generator from single mode laser light source and by inputting light waves having a plurality of wavelengths generated from the multi wavelength generator to wavelength selecting means.

Abstract: A catadioptric objective includes a plurality of optical elements arranged along an optical axis to image a pattern from an object field in an object surface of the objective to an image field in an image surface region of the objective at an image-side numerical aperture NA with electromagnetic radiation from a wavelength band around a central wavelength ?. The optical elements include a concave mirror and a plurality of lenses. The projection objective forms an image of the pattern in a respective Petzval surface for each wavelength ? of a wavelength band, the Petzval surfaces deviating from each other for different wavelengths. In embodiments, a longitudinal departure p of the Petzval surface at a given wavelength from a planar reference surface at an edge field point of the image field (at maximum image height y?), measured parallel to the optical axis in the image surface region, varies with the wavelength ? according to dp/d?<(0.2?/NA2)/nm.

Abstract: Several embodiments of waveguide amplifiers incorporating a network of waveguides, signal splitters, solid state amplifiers and signal combiners are disclosed. The signal splitters and combiners have similar structures including parallel input and exit ports. In some embodiments, the solid state amplifiers are enclosed within the waveguide amplifier.

Abstract: An amplifying optical electromagnetic wave concentrator includes an amplification focusing device and a receiver. The amplification focusing device focuses an incident optical electromagnetic wave on the receiver. The amplification focusing device is doped with active components and is subjected to an excitation wave that causes the active components to pass to an energy level such that interaction between the incident electromagnetic wave and the active components causes the active components to pass to a lower energy level and causes emission, towards the receiver, of at least one photon having the same wavelength as the incident electromagnetic wave. The focused photon or photons form an amplified wave of the incident electromagnetic wave.

Abstract: To avoid harmful nonlinear effects in the amplification of short optical pulses, an initial pulse is divided into a sequence of lower-energy temporally spaced pulses that are otherwise identical to the original pulse. The low-intensity pulses are amplified and then recombined to create a final amplified output pulse.

Abstract: The present invention provides a single fiber bidirectional optical transmission system capable of realizing the extension of a single fiber bidirectional long distance at a moderate price. An optical signal outputted from a second optical transmitter is incident on an optical amplifying portion passing through an optical circulator, a single fiber bidirectional transmission path, an optical circulator and an optical Blue/Red filter. The optical signal outputted from a first optical transmitter is incident on the optical amplifying portion passing through a dispersion compensator and the optical Blue/Red filter.

Abstract: In a laser device, a crystal array includes a laser gain crystal and an optically non-linear frequency conversion crystal. A pump source couples at least two mutually spatially separated pump beams into the crystal array. Between two pump beams, a saw kerf of the crystal array extends parallel to the pump beams.

Abstract: A control apparatus comprises a light monitoring unit for dividing a signal wavelength band into at least a band in which output light power of an optical amplifier tends to decrease at an decrease in the number of signal wavelengths and a band including a gain deviation band, and for monitoring inputted light power for the individual divided bands, a calculation unit for obtaining the number of signal wavelengths in the individual divided bands based on a monitor result, and a target gain correction unit for correcting a target gain based on a result of the calculation. This suppresses a transient variation of signal light level due to SHB or SRS at a high speed with a simple configuration without deteriorating noise characteristic, thus enabling optical amplifiers to be further disposed in a multi-stage fashion, which can lengthen the transmission distance of a transmission system including an optical add/drop unit.

Abstract: A system and method is provided for uniform illumination of a target area. In one embodiment, the system comprises a plurality of mutually incoherent light sources configured to generate respective light beams with different wavelengths, and transmitting optics configured to transmit the light beams with different wavelengths in a non-overlapping wavelength light beam pattern over the target area, such that there are no overlap regions of the target area illuminated by a light beam from the same light source.

Abstract: A method for increasing the number of channels amplified by an optical amplifier arrangement is provided. The optical amplifier arrangement includes at least one optical amplifier stage amplifying a first number of channels at a given average gain level. The method begins by selecting a second number of channels to be amplified by the optical amplifier arrangement. At least one additional optical amplifier stage is serially coupled to an input or output of the at least one optical amplifier stage to form a multistage optical amplifier arrangement. The gain shape of the multistage optical amplifier is adjusted to maintain, at the given average gain level or greater, a prescribed degree of gain flatness over an operating bandwidth in which the second number of channels are located.

Abstract: A system and method for filtering and enhancing signals from a noise background based on the nonlinear interaction of waves. The system and method amplify low-level signals, hide information in the signals, and then nonlinearly recover the signals. With the present invention, this can be performed for both spatial beams and temporal pulses. The signal self-filters and self-amplifies at the expense of the surrounding noise via the nonlinear medium.

Abstract: Methods and apparatus for providing amplification to coarse wave division multiplexing channels or signals are disclosed. According to one aspect of the present invention, an arrangement that adds gain to a set of signals that may be divided into a first band including signals of lower wavelengths and a second band including signals of higher wavelengths includes a multiplexer, first and second optical amplifiers, and a processing arrangement. The multiplexer multiplexes the set of signals. The first optical amplifier has a first gain peak and provides amplification to the set of signals, while the second optical amplifier has a second gain peak and provides amplification to the second band but not to the first band. The processing arrangement passes the second band from the first optical amplifier to the second optical amplifier, and substantially prevents the first band from passing from the first optical amplifier to the second optical amplifier.

Abstract: A bidirectional amplification system and method are disclosed. A single optical line amplifier and isolation loss filters are used to amplify signals in both the east and west directions with sufficient gain along a fiber. In an embodiment, a first signal propagating in a first direction (e.g., east) from a first port and second signal propagating in a second direction (e.g., west) from a second port are received at an optical amplifier module. The first and second signals are combined into a combined signal propagating in one direction. The combined signal is then amplified. The combined signal is then split into amplified first and amplified second signals. The isolation loss of each amplified signal is increased. Then, the amplified first signal propagating in the first direction is output at the second port and the amplified second signal propagating in the second direction is output at the first port.

Abstract: The present invention includes an apparatus and the method to scale the average power from high power ultra-short pulsed lasers, while at the same time addressing the issue of effective beam delivery and ablation, by use of an optical amplification system.

Abstract: A system and method is provided for uniform illumination of a target area. In one embodiment, the system comprises a plurality of mutually incoherent light sources configured to generate respective light beams with different wavelengths, and transmitting optics configured to transmit the light beams with different wavelengths in a non-overlapping wavelength light beam pattern over the target area, such that there are no overlap regions of the target area illuminated by a light beam from the same light source.

Abstract: A thermal nonlinear cell and method. The cell includes a substantially planar nonlinear medium and a mechanism for removing thermal energy from the medium in a direction substantially orthogonal to said medium. In one embodiment, the mechanism for removing thermal energy is a thermally conductive window mounted adjacent to the medium. Preferably, the mechanism includes plural thermally conductive windows between which the nonlinear medium is disposed. In the best mode, the windows are sapphire and the nonlinear medium is a fluid. The windows and the medium are transmissive with respect to first and second beams that interfere with each other and create an interference pattern in the cell. The interference pattern is sampled by a sampling hologram created within the multiple layers of the medium. The interference pattern is used via a sampling hologram to create a phase conjugate of a signal beam. The windows move thermal energy from the medium in a direction transverse to the longitudinal axis of the medium.

Abstract: [Task] To provide the THz wave generator restricting increase in manufacturing cost or large size of the entirety of the apparatus and generating efficiently the several-W THz wave. [Means for Resolution] In a THz wave generator for generating a THz wave from a THz wave generating element by inputting a plurality of laser beams having different wavelengths to the THz wave generating element, at least one laser beam among the plurality of laser beams is formed into a pulse beam by the pulse generator and the pulse beam is amplified by an optical amplifier E and then the pulse beam is inputted to the THz wave generating element F. Preferably, the plurality of laser beams having different wavelengths are generated by inputting single wavelength beam to a multi wavelength generator from single mode laser light source and by inputting light waves having a plurality of wavelengths generated from the multi wavelength generator to wavelength selecting means.

Abstract: Provided is a long cavity single-mode laser diode in which a ring waveguide is integrated such as a conventional array waveguide (AWG)-based laser or a concave grating (CG)-based laser.

Abstract: A phase difference detecting device includes a splitter for splitting laser beams into a first group which will travel along a first path and a second group which will travel along a second path, a beam selection/extraction unit for selecting, as reference light, one beam from the first group to allow it to pass therethrough, a path length changing unit for changing the length of the first path, a combining unit for combining the reference light and beams which construct the second group to produce interference light, and a detector for detecting the intensity of the interference light. The device changes the length of the first path using the path length changing unit to detect a path length which maximizes the intensity of the interference light for each of the beams which construct the second group, and determines a phase difference among the beams from the detected path length.

Abstract: The present invention aims at providing a method for controlling wavelength characteristics of optical transmission powers by Raman amplification, in which the wavelength characteristics of optical transmission powers are automatically compensated without giving any losses to channel lights to thereby improve transmission characteristics, and an apparatus adopting the same. To this end, the method for controlling wavelength characteristics of optical transmission powers by Raman amplification according to present invention supplies Raman pump light to an optical transmission path (Raman amplifying medium); compensates the wavelength characteristics of optical transmission powers caused by transmission of WDM signal light through the optical transmission path, by gain wavelength characteristics of generated Raman amplification; and monitors the wavelength characteristics of optical transmission powers after Raman amplification to thereby control the gain wavelength characteristics of Raman amplification.

Abstract: A multi-band hybrid amplifier is disclosed for use in optical fiber systems. The amplifier uses Raman laser pumps and semiconductor optical amplifiers in series to produce a relatively level gain across the frequency range of interest. Multiple Raman pumps are multiplexed before coupling into the fiber. The Raman amplified optical signal may be demultiplexed and separately amplified by the SOAs before re-multiplexing. Gain profiles of the Raman pumps and the SOAs are selected to compensate for gain tilt and to alleviate the power penalty due to cross-gain modulation in the SOAs. The disclosed hybrid amplifier is especially useful in coarse wavelength division multiplexing (CWDM) systems.

Abstract: A bidirectional amplification system and method are disclosed. A single optical line amplifier and isolation loss filters are used to amplify signals in both the east and west directions with sufficient gain along a fiber.

Abstract: A hybrid beam combining system or method combines a plurality of coherent and incoherent light beams into a composite high power diffraction limited beam. N oscillators each transmit light at one of N different wavelengths and each wavelength is split into M constituent beams. M beams in each of N groups are phase locked by a phase modulator using phase correction signals. The phase locked beams are amplified and coupled into an M×N fiber array. Beams emerging from the array are collimated and incident on a diffractive optical element operating as a beam combiner combining the M outputs at each N wavelength into a single beam. The N single beams are incident and spectrally combined on a grating which outputs a composite beam at a nominal 100% fill factor. A low power sample beam, taken from the N beams emerging from the diffractive optical element, is measured for phase deviations from which the phase correction signals are derived and fed back to the phase modulators.

Abstract: Aspects of the invention can provide an imaging device that can include a first optical element having a first focal length, and a second optical element having a variable second focal length. The second optical element can be located at a fixed first distance of approximately the first focal length away from the first optical element. Thus, such an imaging device can permit an optical system to focus on an object at various distances and at a constant magnification with no moving parts.

Abstract: A polarization-diverse optical amplifier includes a polarization-sensitive optically active medium and a polarization splitter. The polarization splitter is configured to receive input light, to direct a first polarization component of the received input light to a first optical path segment, and to direct a second polarization component of the received input light to a separate second optical path segment. The active medium has first and second optical ports. The first optical port is at an end of the first optical path segment. The second port is at an end of the second optical path segment. The active medium outputs amplified light from one of the ports in response to receiving the input light at the other of the ports. In a preferred embodiment, the active medium has an internal optical axis, and the polarizations of the first and second components are oriented relative to that axis so that amplification is enhanced. The two optical path segments may include polarization-maintaining optical waveguides.

Abstract: The invention provides a two-panel color management system for projection display applications, wherein color sequencing is accomplished using achromatic beam switching and static color separation. In a preferred embodiment, a liquid-crystal polarization switch alternates a polarization of an input light beam between two orthogonal states. A polarization beam splitter directs the beam comprising three primary color components alternately along a first and second paths, wherein first and second different secondary color filters are disposed for forming first and second secondary colored beams, each having two different primary color components. A dichroic color separator alternately receives the first and second secondary colored beams, separates their primary color components and directs them to first and second imager panels. A beam combiner combines the first polarized primary color beam from the first imager and the second polarized primary color beam from the second imager to form a projection beam.

Abstract: An optical receiving device includes an optical receiving element and a light collecting portion having an output surface close to or in contact with the optical receiving surface of the optical receiving element. The dispersion plane at an arbitrary point on the line connecting an arbitrary point on an input surface of the light collecting portion to the optical receiving point where light inputted on the arbitrary point on the input surface is received on the optical receiving surface of the optical receiving element is flat, and the normal to the dispersion plane is parallel to the line.

Abstract: On the upstream side of a quantum dot optical amplifier, a polarization beam splitter with one input and two outputs is provided. Two optical fibers connected to output sections of the polarization beam splitter are connected to input sections of the quantum dot optical amplifier in a state that both of the optical fibers have an electric field whose direction being adjusted to maximize its gain, and one optical fiber is twisted by 90° to the other optical fiber. On the downstream side of the quantum dot optical amplifier, a polarization beam splitter with two inputs and one output is provided. Between two optical fibers connected to the polarization beam splitter, one is twisted by 90° to the other. This twisting direction is reverse to the twisting direction of the two optical fibers connected to the input sections of the quantum dot optical amplifier.

Abstract: A Raman amplifier for amplifying a wavelength division multiplexed (WDM) light including signal lights wavelength division multiplexed together. The amplifier includes an optical amplifying medium and a controller. The optical amplifying medium uses Raman amplification to amplify the WDM light in accordance with multiplexed pump lights of different wavelengths traveling through the optical amplifying medium. The WDM light is amplified in a wavelength band divided into a plurality of individual wavelength bands. The controller controls power of each pump light based on a wavelength characteristic of gain generated in the optical amplifying medium in the individual wavelength bands.

Abstract: A gain-clamped semiconductor optical amplifier is disclosed. The amplifier includes a gain waveguide for amplifying an optical signal input to the gain waveguide, and a grating layer, in contact with the gain waveguide, having a first grating disposed at a first end portion.

Abstract: A multi-band hybrid amplifier is disclosed for use in optical fiber systems. The amplifier uses Raman laser pumps and semiconductor optical amplifiers in series to produce a relatively level gain across the frequency range of interest. Multiple Raman pumps are multiplexed before coupling into the fiber. The Raman amplified optical signal may be demultiplexed and separately amplified by the SOAs before re-multiplexing. Gain profiles of the Raman pumps and the SOAs are selected to compensate for gain tilt and to alleviate the power penalty due to cross-gain modulation in the SOAs. The disclosed hybrid amplifier is especially useful in coarse wavelength division multiplexing (CWDM) systems.

Abstract: A system and method for combining plural low power light beams into a coherent high power light beam. Optical amplifiers transmit a plurality of light beams propagating at a common wavelength through an array of optical fiber emitters. Each constituent beam is emitted from the array at a different propagation angle, collimated, and incident on a diffractive optical element operating as a beam combiner such that incident beams when properly phased and located are combined into a coherent beam at a desired diffraction order. A beam splitter or a periodic sampling grating on the diffractive optical element directs a low power sample beam to a spatial filter passing resonant mode output back to the optical amplifiers in a ring laser configuration thereby passively synchronizing phases of the constituent beams to maximize combination efficiency of the coherent beam.

Abstract: An optical modulation apparatus is provided which implements a stable amplifying function by reducing the effect of reflected light rays form end faces of a bidirectional optical amplifier by imposing a numerical limitation on the relationship between the gain of the bidirectional optical amplifier and the loss of the optical modulator, or by inserting a polarization rotation section in a reflection type optical modulator including the bidirectional optical amplifier or in a multi-wavelength collective optical modulation system combining the multiple optical modulators. An optical modulation apparatus is provided which implements a stable amplifying function and cost reduction by reducing the effect of reflected light rays by interposing optical isolators at every alternate SOAs in a transmission-type optical modulation apparatus including a plurality of semiconductor optical amplifiers (SOAs) connected in a multistage fashion.

Abstract: Methods and devices for coupling the output of multiple emitters of a laser diode bar using a beam transform system with high brightness and coupling efficiency. Some embodiments may include wavelength locking with devices such as VBGs and other suitable devices and methods.

Abstract: Methods and devices for coupling the output of multiple emitters of a laser diode bar using a beam transform system with high brightness and coupling efficiency. Some embodiments may include wavelength locking with devices such as VBGs and other suitable devices and methods.

Abstract: An optical amplifier includes a first optical path, second optical path, semiconductor optical amplifier, and multi-mode interference 3-dB coupler. The first optical path guides oscillation light. The second optical path guides signal light. The semiconductor optical amplifier causes oscillation on the first optical path. The multi-mode interference 3-dB coupler crosses the first and optical paths in the gain medium of the semiconductor optical amplifier.

Abstract: Conventionally, an adjustment of an optical power level of an input Pin of an optical amplifier module is made with an optical variable attenuator. An optical coupler for measuring the optical power level of Pin and an optical variable attenuator are replaced by a variable optical coupler. The branch ratio of the variable optical coupler is varied, whereby the input optical power level Pin to an optical amplifier module is adjusted. As a result, an optical loss is reduced by an amount corresponding to the elimination of the optical attenuator, and also the OSNR of the optical amplifier module is improved.

Abstract: An apparatus for combining laser beams into a single high power output beam. The apparatus includes a self-imaging waveguide (SIWG) with parallel reflective elements that have a length that is an integer multiple of the self-imaging or Talbot length of the waveguide or an integer fraction of this self-imaging length. The apparatus also includes a system for controlling the phase of each of laser beams provided to an inlet of the waveguide. The phases are controlled, e.g., with phase shifters using active feedback or control signals from the inlet to the waveguide, such that a coherently combined beam is produced at the outlet of the waveguide; and this beam is typically a high power beam of 1 kW or higher. The phase shifters are often controlled to phase-lock the input beams and may be operated to steer or aim the output beam from the waveguide.

Abstract: A coherent laser beam combining system wherein the output of a single master oscillator is split into a plurality of signals, the signals are electronically modulated at unique frequencies. One signal is designated a reference signal while the remaining signals are passed through phase adjusters. All signals are optically amplified, aligned and passed through a beam splitter to split off a small sample that is imaged onto a photodetector. The photodetector output is fed to a signal processor that produces phase error signals that drive the phase adjusters resulting in a high-powered optically coherent output signal.

Abstract: An optical fiber amplifier array and related method, in which high beam quality is achieved by varying the frequency of an input signal applied to all of the fiber amplifiers, to locate a frequency at which the amplifiers produce nearly coherent optical outputs. In spite of statistical variations in length and other factors among the fibers, there are frequencies at which the amplifiers produce nearly coherent outputs. In the control system of the invention, the input signal frequency is scanned across a selected narrow range and the beam quality is monitored by measuring on-axis far-field output beam intensity. The frequency is scanned until the beam intensity exceeds a selected threshold, and then the frequency is held constant until the beam intensity falls below a second selected threshold.

Abstract: An optical amplifier includes a first optical path, second optical path, semiconductor optical amplifier, and multi-mode interference 3-dB coupler. The first optical path guides oscillation light. The second optical path guides signal light. The semiconductor optical amplifier causes oscillation on the first optical path. The multi-mode interference 3-dB coupler crosses the first and optical paths in the gain medium of the semiconductor optical amplifier.

Abstract: The invention is in the field of distributed Raman amplification for digital and analog transmission applications and other applications, e.g., instrumentation and imaging applications, including HFC-CATV applications. In particular, the invention uses a high power broadband source of amplified spontaneous emission (ASE) as the Raman pump source for improved system performance. The invention also includes methods for constructing such a high-power broadband Raman pump.

Abstract: An optical signal processing method is disclosed that enables improvements of a signal to noise ratio of an optical signal and reduction of size and power of an optical signal processing device. The optical signal processing method includes steps of dividing an input optical signal into a first polarization optical component and a second polarization optical component orthogonal to the first polarization optical component; supplying the first polarization optical component to a first gain device whose gain saturates at a first value; supplying the second polarization optical component to a second gain device whose gain saturates at a second value less than the first value; combining output light from the first gain device and output light from the second gain device; and outputting the combined optical signal through a polarization element.