Abstract: In each of a plurality of submarine observation apparatus (1 to n), a branching unit (63) branches fixed-wavelength light (?1) from an incoming wavelength-multiplexed light signal. An observation signal modulating unit (64) modulates the intensity of the branched fixed-wavelength light (?1) with observation information multiplexed by an observation signal multiplex unit (61). A combining unit (65) combines light signals (?2) to (?n) passing through the branching unit (63) and the fixed-wavelength light (?1a) modulated by the observation signal modulating unit (64) into a composite light signal, and outputs it to an optical fiber (12a). Therefore, in each of the plurality of submarine observation apparatus (1 to n), there is no necessity for providing a wavelength-division-multiplexing-transmission optical transmitter which requires high wavelength stability.

Abstract: An optical amplifier module is provided that 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 factory 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. The module also includes at least one circuit board on which reside electronics associated with the optical amplifier.

Abstract: A wavelength converter for binary optical signals includes an interferometer structure (110) for generating an output signal by modulating a received local signal (LS) according to the modulation of a fUrther received first input signal (IS 1). When such interferometer structures (110) are operated in a standard mode it is known in the art to control the power of the input signal such that the extinction ratio of the output signal is kept minimal. The invention also controls the power of the input signals to achieve the minimal extinction ratio when the wavelength converter and in particular the interferometer structure (110) is operated in a differential mode receiving two input signals.

Abstract: An improved laser source for use in a distributed temperature sensing (DTS) system (and DTS systems employing the same) includes a laser device and drive circuitry that cooperate to emit an optical pulse train at a characteristic wavelength between 1050 nm and 1090 nm. An optical amplifier, which is operably coupled to the laser device, is adapted to amplify the optical pulse train for output over the optical fiber sensor of the DTS system. In the preferred embodiment, the laser device operates at 1064 nm and outputs the optical pulse train via an optical fiber pigtail that is integral to its housing. The optical power of the optical pulse train generated by the laser source is greater than 100 mW, and preferably greater than 1 W, at a preferred pulse repetition frequency range between 1 and 50 kHz, and at a preferred pulse width range between 2 and 100 ns.

Abstract: An infrared light source includes one or more combiners that are coupled to at least a first pump laser and a second pump laser. The combiners are operable to couple a first optical signal generated by the first pump laser and a second optical signal generated by the second pump laser to a gain fiber, the gain fiber comprising a first waveguide structure. The light source also includes a Raman wavelength shifter that is coupled to the gain fiber. The Raman wavelength shifter being operable to wavelength shift based at least in part on a Raman effect. At least a portion of the Raman wavelength shifter comprising an intermediate waveguide structure that is coupled to a second waveguide structure capable of wavelength shifting at least one wavelength of the first optical signal to an intermediate wavelength in the intermediate waveguide structure and then a longer signal wavelength in the second waveguide structure.

Abstract: An optical direct amplifier lowers the power consumption with a simple structure at a low cost. This amplifier includes an optical amplification medium (e.g., optical fiber) that carries out an optical amplification function in response to optical excitation by an exciting light source (e.g., semiconductor laser); a temperature controller for controlling the temperature of the amplification medium; a heat radiating member for radiating the heat generated by the light source; and a heat transmission regulator (e.g., Peltier module) for allowing the heat to flow into the amplification medium from the light source and for preventing the heat from flowing into the light source from the amplification medium. The amplification medium is heated by application of the heat generated by the light source by way of the heat radiating member and the heat transmission regulator.

Abstract: An optical amplifier including: a first amplifying unit amplifying an input light by utilizing a first excitation light and thereby outputting a first amplified light; a second amplifying unit amplifying the first amplified light by utilizing a second excitation light and thereby outputting a second amplified light; and a control unit detecting a first absorption rate of the first excitation light and a second absorption rate of the second excitation light, and controlling a level of the first excitation light and a level of second excitation light based on the first absorption rate and the second absorption rate. The first absorption rate corresponds to a ratio of the first excitation light absorbed in the first amplifying unit, and the second absorption rate corresponds to a ratio of the second excitation light absorbed in the second amplifying unit.

Abstract: The invention relates to a non-linear optical filter capable of transmitting an electromagnetic pulse with a duration of less than about 1 picosecond, provided with means for generating an electromagnetic field E with a linear polarization from this pulse, and with a crystal C1 of cubic geometry capable of generating an electromagnetic field E?1 from E with a linear polarization orthogonal to that of E. It comprises means for generating at least one other electromagnetic field E?2 capable of producing constructive interferences with the electromagnetic field E?1.

Abstract: A corona detection device includes a bandpass filter having a primary passband that includes at least wavelengths in the range of about 250 nm to about 400 nm and a secondary passband that includes wavelengths in the range of about 675 nm to about 850 nm. The corona detection device also includes an image intensifier in optical communication with the bandpass filter. The image intensifier is configured to generate an image based on radiation passed through the primary passband and the secondary passband of the bandpass filter.

Abstract: A high extraction efficiency laser system. The novel laser system includes a laser amplifier and a laser source adapted to provide a laser beam to the amplifier such that polarization states for incident and reflected light within the amplifier are perpendicular one to another. In an illustrative embodiment, the laser beam is input to the amplifier such that the beam reflects back and forth between the side walls of the amplifier with an angle of incidence of about 45 degrees, and the laser beam is linearly polarized in the plane of incidence. This arrangement reduces interference fringes in the amplifier. In an alternative embodiment, the system includes an aberrator adapted to add time-varying aberrations in the laser beam at a rate exceeding an inversed lifetime of an inverted population in the amplifier to increase spatial homogenization of saturation and extraction patterns in the amplifier.

Abstract: A phosphate glass 1-?m fiber ASE source provides high power and broadband emission that covers wavelengths on the short side of Yb-doped silica. A single-mode fiber formed from phosphate glass is doped with highly elevated concentrations of Yb dopants 0.5-30 wt. % and typically 2-10 wt. %, far higher than either silica or germano-silicate. The high concentration of Yb dopant absorbs the pump in a short length, typically 10-150 cm instead of tens of meters, to provide high saturated output power and a shifted emission spectrum. The excess power allows the fiber ASE source to be configured to provide the output powers, emission bandwidth and stability desired by many applications. Furthermore, the ASE can be configured to emit a nearly Gaussian spectral profile without sacrificing power or bandwidth.

Abstract: The present invention provides an optical amplifying apparatus having: a CPU 11 for processing various signals; a plurality of circuits 17, 18 for controlling respective devices 4, 9 required for optical amplification; a first storing unit 14 for storing a program supplied from a user a gate array 12 for storing various parameters for controlling the devices 4, 9, the gate array being updated based on the program which is stored in the first storing unit 14 and sent via the CPU 11; a latch unit 13, provided between the gate array 12 and the circuits 17, 18, for interrupting a signal path from the gate array 12 to the circuits 17, 18 after receiving a starting signal of an update from the CPU 11 until the update being finished and for controlling the circuits 17, 18 based on the parameters stored in the gate array 12 before the signal path is interrupted; and a second storing unit 16 for, at least during the update, storing the various parameters which are stored in the gate array 12 before the update.

Abstract: The present invention provides a solar-pumped active device which utilizes a holographic antenna grating on a solar energy silicon substrate to select specific diffracted wavelength and couple pump wavelength in an approximately vertical way and converge the pump wavelength to excite an optical gain medium so that an optical amplifier or a laser can be obtained. The present invention requires no big size and is flexible over the surface shape and is suitable for free space optical communications on the ground and satellite optical communications. It means that the holographic antenna grating can be applied on the top floor of a building or on the glass surface of an outer wall. If it is applied to a satellite, the present invention can be deposited on a solar energy cell substrate to form a high optical amplification so that not only the electricity required in satellite optical communications can be reduced, but also a high-speed and large capacity of data can be transferred between satellites.

Abstract: In one aspect the invention relates to a frequency varying wave generator. The generator includes a gain element adapted to amplify a wave having a wavelength; a time varying tunable wavelength selective filter element in communication with the gain element, the tunable filter element adapted to selectively filter waves during a period T; and a feedback element in communication with the tunable filter element and the gain element, wherein the tunable wavelength selective filter element, the gain element and the feedback element define a circuit such that the roundtrip time for the wave to propagate through the circuit is substantially equal to a non-zero integer multiple of the period T.

Abstract: A waveguide amplifier, disposed on a substrate, composed of sputtered film of chalcogenide glass doped with Erbium is disclosed. The amplifier includes a substrate, a thick film of chalcogenide glass disposed on the substrate, a pumping device, and an optical combining device, wherein the waveguide is operable to amplify the optically combined signal. This type of amplifier has been shown to be compact and cost-effective, in addition to being transparent in the mid-IR range as a result of the low phonon energy of chalcogenide glass.

Abstract: In one embodiment, a high frequency quasi optical oscillator power source is provided which includes an array of amplifier devices each having an input antenna tuned for a fundamental frequency. A amplifier coupled to the input antenna amplifies fundamental frequency signals. A multiplier coupled to the amplifier provides signals at a multiple of the fundamental frequency and at the fundamental frequency. The output antenna coupled to the multiplier is tuned at the fundamental frequency and at a multiple of the fundamental frequency. A grating lobe-to-main lobe converter located above the array of amplifier devices converts grating lobe power to main lobe power at the multiple of the fundamental frequency. A frequency selective reflector opposes the amplifier array to reflect signals at the fundamental frequency and to pass signals at the multiple of the fundamental frequency.

Abstract: A method for determining gain for an optical signal includes measuring a first power level that is an output power level of an optical signal at a first optical node, communicating the optical signal to a second optical node, and communicating the first power level to the second optical node in an optical supervisory channel of the optical signal. The method further includes receiving the optical signal at the second optical node, measuring a second power level of the optical signal at the second optical node, and determining a gain for the optical signal based on the first and second power levels.

Abstract: The present invention relates to a system for detection and identification of airborne biological, chemical and/or nuclear threats such as toxins, spores, bacteria, and viruses in real time at distances from a few meters to several kilometers. Compact femtosecond terawatt laser technology is combined with spectroscopic and mathematical methods for spectral sensing of airborne warfare agents such as bio-aerosols. Trigger sensors and standoff devices based on mobile terawatt femtosecond laser systems are provided that may be placed at strategic monitoring locations. Furthermore, the invention relates to the propagation of airborne ultra-short, ultra-intense laser pulses giving rise to plasma channels (filamentation) producing white light supercontinuum ranging from the ultraviolet (UV), visible (VIS), near infra-red (NE) and middle infra-red (MIR).

Abstract: A high extraction efficiency laser system. The novel laser system includes a master oscillator for providing a laser beam, an amplifier adapted to amplify the laser beam, and an aberrator for aberrating the laser beam to prevent the formation of caustic intensity patterns within the amplifier. In an illustrative embodiment, the laser system also includes a depolarizer disposed between the master oscillator and the amplifier to reduce the contrast of speckle intensity patterns in the amplifier, and a mechanism adapted to rotate or otherwise move the aberrator to time-vary the aberrations in the beam in order to increase the spatial homogenization of saturation and extraction patterns in the amplifier. In a preferred embodiment, the coherence length of the beam is also shortened to reduce interference fringes in the amplifier.

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: The present invention relates to a method for optical fiber transmission which can increase a transmission distance. A first optical fiber having dispersion is first provided. An optical signal is next supplied to the first optical fiber so that the optical signal is compressed on the time axis as propagating in the first optical fiber. In the case that the dispersion is normal dispersion, for example, prechirping is performed so that the optical signal has down-chirp. A compressed optical signal output from the first optical fiber is supplied to an optical device having a saturated gain. According to this method, the transmission distance can be increased by the effective combination of compression of the optical signal and waveform shaping by the optical device.

Abstract: The wavelength converter comprises (1) an optical multiplexer for multiplexing an amplitude-modulated first light and reference light, which is continuous light having a wavelength different from the wavelength of the first light, (2) an optical fiber for propagating the multiplexed light therethrough to generate a third light by a non-linear optical phenomenon, and (3) an optical filter having a pass wavelength range set such that a pulse time width of the third light is 20% or more narrower than a pulse time width of the first light after the third light has passed through the optical filter, or (3?) an optical filter having a pass wavelength range set such that a cross point of an eye pattern of the third light is lower than a cross point of an eye pattern of the first light after the third light has passed through the optical filter.

Abstract: An optical attenuator is included within an aircraft decoy driver system for driving a fiber optic towed decoy system to compensate for variability in the fiber optic connection to the towed decoy system. The attenuator is controlled by a control signal from the towed decoy system and adjusts the link gain based on this feedback control signal to compensate for link loss, which is highly variable and may include losses as a function of cable, connectors and splices, and to maintain a relatively constant gain. To ensure the broadest range of performance, a higher power laser can be used to drive an external Mach Zhender Modulator or an erbium doped fiber amplifier (EDFA) prior to the optical attenuator. The result is a fiber optic towed decoy system that is adaptable to various platforms and design configurations without degradation in performance of the towed decoy system.

Abstract: A method and apparatus, in some embodiments the apparatus includes a flex cable terminating at a first end and a second end and having a plurality of conductors therein, and a repeater circuit disposed between the first end and the second end and connected to at least one of the plurality of conductors to re-transmit a signal transmitted on the at least one of the plurality of conductors.

Abstract: A regenerator for restoring the originally encoded optical phase of a differential-phase-shift-keyed signal. In an embodiment, the regenerator simultaneously provides limiting amplification and reduces amplitude noise based on a phase-sensitive optical amplifier that combines a weak signal field of a degraded input data with a strong pump field supplied by a local oscillator in a nonlinear interferometer. The two fields interact through degenerate four-wave mixing, and optical energy is transferred from the pump to the signal and vice versa. The phase sensitive nature of the optical gain leads to amplification of a specific phase component of the signal, determined by the input pump-signal phase difference and the incident signal phase is restored to two distinct states, separated by 180° according to the original encoding. Simultaneously, gain saturation of the pump wave by the signal wave results in limiting amplification of the signal wave for removing signal amplitude noise.

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 system for sensing characteristics of the environment is disclosed. Sensors utilize exponential growth of a signal initiated by interaction of a sensor element with characteristics of the environment. Specific substances in the environment can be detected. The sensor element may be intrinsically sensitive to the specific substance or can be coated with a material that is sensitive to the specific substance. The sensor component is designed such that it can be made to cause exponential growth of a system signal. The exponential growth of the sensor signal is produced by parametric amplification.

Abstract: An optical amplifier reducing gain deviation caused by wavelength arrangement has a first-stage optical amplifying unit, an attenuator, a second-stage optical amplifying unit, an automatic gain controller controlling the first- and second-stage optical amplifying units so that a gain of signal light outputted from the second-stage optical amplifying unit to signal light inputted to the first-stage optical amplifying unit is constant, and an attenuation amount controller controlling an attenuation amount at the attenuator to adjust gain-versus-wavelength characteristic at the automatic-gain-controlled first- and second-stage optical amplifying units on the basis of information on wavelength arrangement and an input level of the signal light inputted to the first-stage optical amplifying unit so that gain slope characteristic at the first- and second-stage optical amplifying units due to the wavelength arrangement and the input level is flattened.

Abstract: An optical transmission system includes an optical fiber transmission line, one or more optical repeating apparatuses, an optical receiving apparatus, and a transferring route for transferring a supervisory signal based on a quality deterioration of an optical signal detected by the optical receiving apparatus to the optical repeating apparatus from the optical receiving apparatus. The optical repeating apparatus includes an optical level variation detecting unit for detecting a level variation of an optical signal and a level variation storing unit for storing information based on the level variation.

Abstract: The present invention provides an optical switch including a loss element having a signal loss, and a rare earth doped gain element optically connected in series with the loss element. The rare earth doped gain element is operable to produce a signal gain. The signal gain and the signal loss are about equal. The present invention also provides a method of optical switching including optically connecting a loss element in series with a rare earth doped gain element and passing an optical signal through the loss element and the gain element. The loss element attenuates the optical signal by a first amount. The method further includes selectively applying an optical pump to the gain element to perform the switching, the gain element amplifying the optical signal by the first amount in response to the optical pump.

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: 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: Control of average wavelength-converted power and/or wavelength converted pulse energy is described. One or more seed pulses may be generated and amplified with an optical amplifier to produce one or more amplified pulses. The amplified pulses may be wavelength converted to produce one or more wavelength converted pulses characterized by an average wavelength-converted power or pulse energy. Wavelength-converted power or pulse energy may be controlled by adjusting wavelength conversion efficiency without substantially changing the amplified power or pulse energy. Average wavelength-converted power may be controlled over a time scale comparable to a pulse period of the amplified pulses without adjusting an average power of the amplified pulses over the time scale comparable to a pulse period of the amplified pulses.

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 optical amplifier is disclosed having a substantially uniform spectral gain. In an exemplary embodiment, the optical amplifier comprises a planar waveguide including a substrate, which includes a region doped with rare earth element. The optical amplifier also comprises an optical fiber including a core doped with the rare earth element. The optical fiber is optically coupled to the planar waveguide.

Abstract: The present invention provides a neodymium doped, transparent electro-optic gain ceramic material consisting lead, zirconium, titanium and lanthanum. The electro-optic gain ceramic material either has a linear electro-optic coefficient or a quadratic electro-optic coefficient, which is greater than about 0.3×10?16 m2/V2 for the latter, a propagation loss of less than about 0.3 dB/mm, and an optical gain of great than 2 dB/mm at a wavelength of about 1064 nm while optically pumped by a 2 watts diode laser at a wavelength of 802 nm at 20° C. The present invention also provides electro-optic devices including a neodymium doped, transparent electro-optic gain ceramic material consisting lead, zirconium, titanium and lanthanum. The present invention also provides lossless optical devices and amplifiers with an operating wavelength in the range of 1040 nm to 1100 nm while optically pumped at a wavelength in the range of 794 nm to 810 nm.

Abstract: An optical amplifier comprises a printed circuit board (PCB) having at least one support layer of electrically non-conducting material and at least one conductive layer of electrically conducting material, and a foil heater in the form of a conductive track 20 on the PCB. A specified length of erbium optical fibre is wound around an aluminium spool mounted on the PCB and clamped by a clamp with the interposition of a thermal gasket, so that the optical fibre can be heated by the heater. Cutouts are provided in the PCB surrounding the heater to minimise loss of heat from the heater. The form of the heater enables it to be produced during fabrication of the optical fibre without utilising additional costly fabrication steps.

Abstract: An ultraviolet light source (1) comprises a laser light source (10) for generating a signal light in the infrared region, a optical amplifier (20) which comprises fiber optical amplifiers (21, 22) and amplifies the signal light generated by the laser light source (10), and a wavelength converting optical system (30) which coverts the signal light amplified by the light amplifier (20) into an ultraviolet light and outputs the converted light. The ultraviolet light source (1) uses a single-mode fiber laser (26) as an excitation light source for at least the fiber optical amplifier (22) at one stage of the optical amplifier (20).

Abstract: A semiconductor optical amplifier device includes an active layer, an n-type InP substrate, an n-type InP clad layer, a p-type InP clad layer, p-electrodes and n-electrodes. The active layer is made of, e.g., InGaAsP, and includes a saturable absorption region and optical amplification regions. A common modulated current is injected into each optical amplification region through the p-electrode. A modulated current is injected into the saturable absorption region through the p-electrode independently of the optical amplification region. The active layer receives injection light produced by adding additional noise light to an externally applied light signal, and emits output light produced by amplifying the injection light.

Abstract: A quasi-monochromatic light beam carrier for a particular telecommunication channel is likely to experience drift because of age, temperature, or other factors, and may cause the centroid wavelength of the carrier to shift. Temperature adjustments by wavelength lockers to compensate for drift on one channel may affect the performance of other channels. Embodiments of the present invention couple a quasi-monochromatic light beam through a substrate-based grating, diffract the light beam from the edge of the substrate to free space, and detect the light beam from free space at a position detector to determine the centroid wavelength based on a position of the light beam incident on the detector. The diffracted light beam may be reflected within the substrate a number of times prior to exiting the substrate towards the detector.

Abstract: An electroabsorption (EA) duplexer in which an optical amplifier, a photodetector, and an optical modulator are monolithically integrated to obtain a high radio frequency (RF) gain in radio-over fiber (RoF) link optical transmission technology is provided. The EA duplexer includes a substrate, a separation area, an optical detection/modulation unit, and an optical amplification unit. The separation area includes a first epitaxial layer formed of at least one material layer on the substrate. The first epitaxial layer functions as a first optical waveguide. The optical detection/modulation unit includes a second epitaxial layer formed of at least one material layer on the first epitaxial layer to detect and modulate an optical signal. The second epitaxial layer functions as a second optical waveguide. The optical amplification unit includes the second optical waveguide and a third epitaxial layer formed of at least one material layer on the second epitaxial layer to amplify an optical signal.

Abstract: In an optical amplifier, passively wavelength-stabilized pump diodes generate pumping light to excite a gain medium (e.g., rare-earth-ion doped optical fiber or solid-state optical amplifier) near an absorption peak of the gain medium. The gain medium amplifies a pulsed laser signal coupled into the gain medium to a high peak power with minimal non-linear distortion. The gain medium may include a portion configured to receive the pumping light and another portion configured to amplify the pulsed laser signal. A volume phase hologram device may passively wavelength stabilize the pump diodes by reflecting a portion of the pumping light back to the pump diodes. Passively wavelength-stabilizing the pump diodes improves power efficiency of the optical amplifier.

Abstract: The lifetime of optical components used in deep-UV (DUV) excimer laser systems, including systems in a MOPA configuration, can be increased by reducing the intensity of pulses incident upon these components. In one approach, an output pulse can be “stretched” in order to reduce the peak power of the pulse. A pulse stretching component can be used, which can be mounted outside the laser enclosure with a horizontal beam path in order to provide a delay line with a minimum impact on the laser system footprint. The horizontal beam path also can minimize the number of optical components in the arm containing the high power beam. A beamsplitting prism can be used with the delay line to avoid the rapid degradation of coatings otherwise exposed to intense UV beams. The prism can expand the beam in the delay line in order to minimize beam intensity and losses due to reflection.

Abstract: An apparatus and method for building three-dimensional spatial power combiners for efficiently combining power from a large number of active devices are being disclosed. The apparatus discloses a plurality of grid amplifiers, each having a major surface, the plurality of grid amplifiers are arranged along an axis that is perpendicular to the major surface of each grid amplifier and spatially separated from each other by a selected resonant distance to generate a standing wave between adjacent grid amplifiers. The method discloses selecting a plurality of grid amplifiers each having a major surface, arranging the plurality of grid amplifiers along an axis that is perpendicular to the major surface of each grid amplifier, selecting a resonance distance, and spatially separating said plurality of grid amplifiers by the resonant distance to generate a standing wave between adjacent grid amplifiers.

Abstract: Bidirectional isolating devices including non-reciprocal rotators (i.e. Faraday rotators) and wavelength selective reciprocal polarization rotators are disclosed. Each wavelength selective rotator behaves like a half-wave retarder in a first frequency range and behaves like a full-wave retarder in a second frequency range, according to a substantially periodic transfer function. The rotation has a predetermined number of birefringent elements (e.g. waveplates), the thickness and the orientation of which are chosen so as to obtain a transition between the half-wave retarder behavior and the full-wave retarder behavior in a frequency range lower than or equal to 40% of the period of the transfer function. In order to satisfy such a requirement, a relatively high number of birefringent elements is required, i.e. at least the five birefringent elements. Advantageously, the isolating device may comply with any allocation scheme for the opposite propagating signals.

Abstract: An optical frequency comb generator includes an oscillator (117) for oscillating modulating signals of a preset frequency, and an optical resonator (110) formed by an incident side reflecting mirror (112) and an outgoing side reflecting mirror (113), arranged parallel to each other. The optical resonator causes resonation in light incident via the incident side reflecting mirror (112). The optical frequency comb generator also includes an optical phase modulation unit (111) arranged between the incident side reflecting mirror (112) and the outgoing side reflecting mirror (113) for phase modulating the light, resonated by the optical resonator (110), by the modulating signals supplied from the oscillator (117), and for generating a plurality of sidebands centered about the frequency of the incident light at a frequency interval of the modulating signal. The outgoing side reflecting mirror (113) sets the transmittance from one frequency to another responsive to the light intensity of the generated sidebands.

Abstract: A large mode area, gain-producing optical fiber is configured to support multiple transverse modes of signal radiation within its core region. The fiber is a hybrid design that includes at least two axial segments having different characteristics. In a first axial segment the transverse refractive index profile inside the core is not radially uniform being characterized by a radial dip in refractive index. The first segment supports more than one transverse mode. In a second axial segment the transverse refractive index profile inside the core is more uniform than that of the first segment. The two segments are adiabatically coupled to one another. Illustratively, the second segment is a terminal portion of the fiber which facilitates coupling to other components. In one embodiment, in the first segment M12>1.0, and in the second segment M22<<M12. In a preferred embodiment, M12>>1.0 and M22˜1.0.

Abstract: The device comprises an optical waveguide and an acoustic wave generating device. The waveguide has an optical band gap and a sharp electronic transition (e.g. an excitonic transition) in the band gap, and the acoustic wave generating device generates acoustic waves within the waveguide. Light passing through the waveguide is of a frequency within the band gap of the waveguide and is nearly resonant with the sharp electronic transition. The wave generating device is arranged to generate acoustic waves so as to induce optical band gas in the polariton spectrum, thereby affecting the transmission of the light passing through the waveguide, the transmission of which is thereby affected.

Abstract: An optical device comprises a first substrate wafer with at least one buried optical waveguide on an approximately flat planar surface of the substrate and a second substrate wafer with at least a second buried optical waveguide. The waveguides so formed may be straight or curved along the surface of the wafer or curved by burying the waveguide at varying depth along its length. The second wafer is turned (flipped) and bonded to the first wafer in such a manner that the waveguides, for example, may form an optical coupler or may cross over one another and be in proximate relationship along a region of each. As a result, three dimensional optical devices are formed avoiding the convention techniques of layering on a single substrate wafer.

Abstract: The invention describes a system of two-stage optical amplifiers adapted for inserting OADM in the mid-stage, and an integrated assembly designed for implementing the amplifiers in a way suitable for forming bi-directional configurations useful in optical networks. A so-called east-west configuration for a bi-directional transmission is described, where each direction of the optical transmission is served by the two-stage optical amplifier the 1st stage of which belongs to one integrated assembly, and the 2nd stage—to another assembly.