Abstract: Apparatus include a first optical fiber including a core situated to propagate a signal beam at a signal wavelength and an unwanted stimulated Raman scattering (SRS) beam at an SRS wavelength associated with the signal wavelength, and a fiber Bragg grating (FBG) situated in a core of a second optical fiber optically coupled to the core of the first optical fiber, the FBG having a selected grating reflectivity associated with the SRS wavelength and being situated to reflect the SRS beam back along the core of the second optical fiber and to reduce a damage associated with propagation of the SRS beam to power sensitive laser system components optically coupled to the second optical fiber. Methods are also disclosed.

Abstract: The present disclosure proposes a non-baseline on-line stress monitoring system and monitoring method based on multi-mode Lamb wave data fusion. A Lamb wave dispersion curve is established according to geometric dimensions and material parameters of a measured object, a cut-off frequency of a first-order Lamb wave mode is obtained, an excitation frequency of a Lamb wave signal is determined, and then pure Lamb waves in S0 and A0 modes obtained inside the measured object are obtained; an acoustoelastic equation is established, an elastodynamic equation of the measured object under a prestress condition is solved, and linear relationships between a group velocity and a stress of the Lamb waves in the S0 and A0 modes under the excitation frequency are obtained; data is processed through the on-line monitoring system; a stress gradient in a depth direction is calculated, and finally, a stress state of the measured object is represented.

Abstract: System, method, and instrumentalities are described herein for transmitting information optically. The optical source may be configured to generate a beam. The beam may include a series of light pulses. The beam of light may be modulated. A modulator may be configured to modulate the series of light pulses in response to a data transmission signal, thereby encoding transmission data into the series of light pulses. The modulated beam of light may be received and both amplified and filtered. The filtered beam of light may be transmitted from to a detector having a photoreceiver. The photoreceiver may be configured to extract the transmission data from the filtered beam of light.

Abstract: A method of spectral beam-combining an array of fiber optics is disclosed. Each fiber may be coupled to a high-power, wavelength-stabilized, fiber-coupled, diode-laser module and has a fiber-by-fiber pre-selected wavelength. The wavelengths may be chosen such that the array can be spectrally combined on, for example a transmission grating and re-focused into an output fiber. This approach is scalable to, for example, 10 kW power and have a beam quality sufficient for metal cutting applications.

Abstract: Systems and methods are provided for controlling one or more optical amplifiers of a C+L band photonic line system (30) of a telecommunications network in which C-band signals and L-band signals may be transmitted. In one implementation, a method (130) may execute a traffic managing module (23). When executed, the traffic managing module (23) may be configured to enable a processing device (12) to calculate (132) a gain correction profile based on a difference between a saved baseline transmission profile (84) and a measured transmission profile (94) of a surviving band of a photonic line system (30) when another band of the photonic line system (30) is missing or impacted. The traffic managing module (23) may further be configured to enable the processing device (12) to apply (134) the gain correction profile to a respective optical amplifier (46) of the photonic line system (30) to compensate for the difference.

Abstract: System, method, and instrumentalities are described herein for transmitting information optically. The optical source may be configured to generate a beam. The beam may include a series of light pulses. The beam of light may be modulated. A modulator may be configured to modulate the series of light pulses in response to a data transmission signal, thereby encoding transmission data into the series of light pulses. The modulated beam of light may be received and both amplified and filtered. The filtered beam of light may be transmitted from to a detector having a photoreceiver. The photoreceiver may be configured to extract the transmission data from the filtered beam of light.

Abstract: A distributed acoustic sensing (DAS) system based on random fiber lasing amplification (RFLA) and a Rayleigh scattering enhanced fiber (RSEF), and relates to the field of distributed optical fiber sensing. The system comprises a DAS demodulation unit, a high-order RFLA unit and a RSEF. The present disclosure adopt the high-order RFLA technology to replace the traditional high-order distributed Raman amplification technology, and it does not need to use a plurality of pumps with different wavelength, and only needs a high-order random fiber laser pump and a broadband reflector to provide feedback for cascaded random fiber lasings to perform distributed amplification on signal light. By using high-order RFLA combined with the RSEF, high-efficiency and low-threshold RFLA can be achieved, and the signal-to-noise ratio and performances of a DAS system can be further improved, which enables realization of long-distance and high-performance distributed acoustic sensing.

Abstract: Methods and system to provide high power and brightness display and illumination systems and methods. In embodiments multi-wavelength laser beams in the wavelength range of 300 nm to 700 nm, including high power beams in these wavelengths having excellent beam qualities are provided and used. The three wavelengths can be primary colors, red, green and blue. Manufacturing and display systems, allowing the high-power white light generation directly from a single fiber laser source, such as theaters, sporting events, public events, private and home entertainment to name a few. The systems are configured for Photopic and Scotopic vision.

Abstract: An optical system for suppressing signal noise on an optical fiber, including an input power signal; a pump laser configured to receive the input power signal; a phase modulator coupled to the pump laser configured to modulate, in response to the input power signal, a phase of the pump laser to increase a stimulated Brillouin scattering (SBS) threshold of the pump laser, wherein the pump laser is further configured to: increase a power at the pump laser to be greater than the SBS threshold; generate a back scattering power based on the power of the pump laser being greater than the increased SBS threshold; and limit an output power signal of the pump laser based on the generated back scattering power.

Abstract: A controller for a front-exciting Raman-amplifier that amplifies an optical signal transmitted from one end of an optical fiber to other end by inputting an excitation light to the one end, the controller includes a memory, and a processor coupled to the memory and configured to acquire communication-related information regarding communication of the optical signal in the optical fiber, when the acquired communication-related information does not indicate the communication of the optical signal, set a Raman gain of the front-exciting Raman amplifier based on a first light intensity of an amplified spontaneous scattered light of the excitation light, and when the acquired communication-related information indicates the communication of the optical signal, set the Raman gain based on a second light intensity of the optical signal output from the optical fiber.

Abstract: A broadband optical amplifier for operation in the 2 ?m visible wavelength band is based upon a single-clad Ho-doped fiber amplifier (HDFA). A compact pump source uses a combination of discrete laser diode with a fiber laser (which may be a dual-stage fiber laser) to create a pump output beam at a wavelength associated with creating gain in the presence of Ho ions (an exemplary pump wavelength being 1940 nm). The broadband optical amplifier may take the form of a single stage amplifier or a multi-stage amplifier, and may utilize a co-propagating pump and/or a counter-propagating pump arrangement.

Abstract: A Raman pumping device (10) for amplifying a data optical signal in a fiber optic transmission system, comprising first and second ports (12a, 12b) through which the data optical signal may respectively enter and exit the Raman pumping device (10), a Raman pump source (14) for generating a Raman pump signal, and at least one combiner (16) for combining the Raman pump signal with the data optical signal. The Raman pumping device (10) allows for selectively combining the Raman pump signal generated by the same Raman pump source (14), or at least parts of the same Raman pump source (14) codirectionally or counterdirectionally with the data optical signal.

Abstract: A fiber laser device includes: an amplifying fiber; a delivery fiber in which laser light that has been outputted from the amplifying fiber is guided; and a Raman filter that reflects part of Raman scattered light that is generated by stimulated Raman scattering caused to the laser light.

Abstract: Prescribed mathematical expressions are satisfied, where ?0 represents a wave number indicating a peak corresponding to a folded mode of a longitudinal optical branch of a Raman spectrum of silicon carbide having a polytype of 4H and having zero stress, ?max represents a maximum value of a wave number indicating a peak corresponding to a folded mode of a longitudinal optical branch of a Raman spectrum of a silicon carbide substrate in a region from a first main surface to a second main surface, ?max represents a minimum value of the wave number indicating the peak corresponding to the folded mode of the longitudinal optical branch of the Raman spectrum, and ?1 represents a wave number indicating a peak corresponding to a folded mode of a longitudinal optical branch of a Raman spectrum of the silicon carbide substrate at the first main surface.

Abstract: A fiber laser apparatus includes a pump light source that emits pump light; a pump delivery fiber that guides the pump light; an amplifying optical fiber that is optically coupled to the pump delivery fiber and guides laser light; and a filter element that causes more loss of light of a wavelength range that includes a peak wavelength of at least one of Stokes light and anti-Stokes light than the laser light. The Stokes light and anti-Stokes light result from four-wave mixing involving a plurality of guide modes in a multi-mode fiber that guides the laser light. The filter element is disposed between: the pump delivery fiber and the amplifying optical fiber, the amplifying optical fiber and the multi-mode fiber, or at the multi-mode fiber.

Abstract: The present disclosure relates to optical communications, and in particular, to a DWDM remote pumping system for improving an OSNR. The system includes remote pumping gain unit, preamplifier, and gain flattening filter sequentially connected. Remote pumping gain unit and preamplifier are cascaded one behind the other as a whole amplifier. Gain flattening filter is disposed at the preamplifier's output end. In the system, remote gain unit and preamplifier which have large impact on the OSNR of the entire system are optimally designed as a whole amplifier. In remote gain unit, gain flattening filter originally disposed between two erbium-doped fiber segments is moved back to preamplifier's output end for significant improvement of gain and noise figures of the remote gain unit while ensuring gain flatness of the entire transmission system, thus effectively improving the entire system's OSNR, improving operation stability and reliability, effectively reducing bit error rate, and facilitating system maintenance.

Abstract: The present disclosure relates to a technical field of optical communication, and provides a method and an apparatus for determining maximum gain of Raman fiber amplifier. Wherein the method includes obtaining transmission performance parameters of a current optical fiber transmission line; respectively obtaining impact factors A1, A2, A4 according to a distance between a joint and a pump source, a fiber loss coefficient, and a fiber length included in the transmission performance parameters; calculating a joint loss value AttAeff according to a distance between a joint and a pump source, a fiber loss coefficient, and looking up impact factor A3 according to AttAeff; determining an actual maximum gain which may actually be achieved by the Raman fiber amplifier according to A1, A2, A3, A4.

Abstract: The invention relates to a method for migrating data traffic from an existing optical WDM transmission system to a new optical WDM transmission system, the existing optical WDM transmission system using a first optical transmission band and the new optical WDM transmission system being capable of using a second optical transmission band. The second optical transmission band at least partially includes the first optical transmission band and a further extension band that does not overlap with the first optical transmission band, the method including the steps of. According to the invention, a migration filter device is used in order to connect, during a migration phase, the network nodes of the existing system and the network nodes of the new system to the network paths that have been used by the existing system. During the migration phase, both systems are operated in parallel, with the new system using the extension band only.

Abstract: A system and method for high speed communication are provided. The system comprises a laser-based system for communication, the system comprising: an acquisition module configured to acquire and characterize a plurality of laser beams; a tracking module configured to track the acquired laser beams, the tracking module comprising: a beaconing feedback and beam divergence mechanism configured to control a beam and detect a beam; an adaptive learning unit configured to implement an adaptive learning detection algorithm to identify and track a unique optical signature from at least one of the acquired laser beams; and a pointing module configured to point at least one laser beam towards a target based on the acquired laser beams.

Abstract: A low-noise amplifier includes a gain medium and two or more amplifier stages. Each amplifier stage includes an optical filter to pass all wavelengths of a respective input optical signal in a given propagation direction over the gain medium and reflect wavelengths above a respective threshold wavelength received in the opposite direction, and a respective Raman pump to inject a pump light centered at a wavelength lower than the threshold wavelength onto the gain medium for transmission in the given direction. A first amplifier stage outputs a first combined optical signal including all wavelengths of the respective input optical signal and a pump light injected by the respective Raman pump. The second amplifier stage receives the first combined optical signal as its input and outputs a second combined optical signal including all wavelengths of the first combined optical signal and a pump light injected by the respective Raman pump.

Abstract: This disclosure describes C and L band optical communications module link extender, and related systems and methods. An example method may include receiving, by a dense wave division multiplexer (DWDM) at a headend, one or more optical data signals over a C band and an L band. The example method may also include combining the one or more optical data signals. The example method may also include outputting the combined one or more optical data signals to a first WDM at the headend. The example method may also include separating, by the first WDM, the combined one or more optical data signals into a C band signal and an L band signal. The example method may also include outputting the C band signal to a first amplifier at the headend and the L band signal to a second amplifier at the headend. The example method may also include amplifying, by the first amplifier, the C band signal. The example method may also include outputting the amplified C band signal to a coexistence filter.

Abstract: A signal light interruption detection device includes an optical interleaver to demultiplex wavelength-multiplexed light into light in first frequency ranges corresponding to a first frequency grid including frequencies at regular frequency intervals in which a main signal light component can be arranged and light in second frequency ranges corresponding to a second frequency grid shifted from the first frequency grid by a half cycle of the regular frequency intervals, a first optical detector to detect first light power as total power of the light in the first frequency ranges, a second optical detector to detect second light power as total power of the light in the second frequency ranges, and a judgment unit to output a notification signal based on a difference between the first light power detected by the first optical detector and the second light power detected by the second optical detector.

Abstract: A semiconductor laser source including a Mach-Zehnder interferometer, this interferometer including first and second arms. Each of the arms is divided into a plurality of consecutive sections, the effective index of each section located immediately after a preceding section being different from the effective index of this preceding section. The lengths of the various sections meet the following condition: ? n = 1 N 2 ? L 2 , n ? neff 2 , n - ? n = 1 N 1 ? L 1 , n ? neff 1 , n = k f ? ? Si where: kf is a preset integer number higher than or equal to 1, N1 and N2 are the numbers of sections in the first and second arms, respectively, L1,n and L2,n are the lengths of the nth sections of the first and second arms, respectively, neff1,n and neff2,n are the effective indices of the nth sections of the first and second arms, respectively. The first and second arms each comprise a gain-generating section.

Abstract: An optical system including a forward and a backward Raman pump module positioned along a transmission fiber; a noise matrix computing module configured to: determine, for first gains of the optical signal, a first noise associated with the first gain of the forward Raman pump; determine, for second gains of the optical signal, a second noise associated with the second gain of the backward Raman pump module; generate a noise matrix based on i) the first noise for each first gain of the forward Raman pump module and ii) the second noise for each second gain of the backward Raman pump module; identify a span loss of the optical signal as the optical signal is transmitted along the transmission fiber; identify a combination of a particular first gain of the forward Raman pump module and a particular second gain of the backward Raman pump module.

Abstract: An optical amplifier includes a polarization splitter, a polarization rotator, first and second optical couplers, and first and second semiconductor optical amplifying devices. The TE polarized wave of light split by the polarization splitter is input to a first input port of the first optical coupler. The TM polarized wave of the split light is converted into a TE polarized wave by the polarization rotator to be input to a second input port of the first optical coupler. First light and second light output from a first output port and a second output port of the first optical coupler are amplified by the first semiconductor optical amplifying device and the second semiconductor optical amplifying device to be input to a first input port and a second input port of the second optical coupler, respectively. Third light is output from an output port of the second optical coupler.

Abstract: Systems and methods are provided for controlling one or more optical amplifiers of a C+L band photonic line system of a telecommunications network in which C-band signals and L-band signals may be transmitted. In one implementation, a control device may include a processing device and a memory device configured to store a traffic managing module for controlling C-band and the L-band traffic in the photonic line system. The traffic managing module, when executed, may be configured to cause the processing device to calculate a gain correction profile based on a difference between a saved baseline transmission profile and a measured transmission profile of a surviving band of a photonic line system when another band of the photonic line system is missing or impacted. The traffic managing module is configured to apply the gain correction profile to a respective optical amplifier of the photonic line system to compensate for the difference.

Abstract: A laser apparatus includes: a master oscillator for emitting a laser beam; an amplifier on an optical path of the laser beam; a beam splitter between the master oscillator and the amplifier for separating, from the optical path of the laser beam, at least part of a return beam traveling through the optical path of the laser beam in a direction opposite to a traveling direction of the laser beam; a focusing optical system for focusing the return beam separated from the optical path; and an optical sensor having a light receiving surface for the return beam for detecting information on power of the return beam entering the light receiving surface through the focusing optical system, the light receiving surface being arranged at a position different from a focusing position of the focusing optical system on the optical path of the return beam.

Abstract: Apparatus for optical isolation, which apparatus comprises a laser (1), a beam delivery system (91), and an output port (92), wherein: the beam delivery system (91) comprises an optical isolator (8) and an optical fibre (2); the laser (1) is defined by a peak power (21); the laser (1) emits laser radiation (13) at a signal wavelength (19); the laser radiation (13) is coupled from the laser (1) to the output port (92) via the beam delivery system (91); and the optical fibre (2) comprises an optical waveguide (100) defined by a core (101), a cladding (102), a mode field area (104) at the signal wavelength (19), a length (86), and a Raman wavelength (25); and the apparatus being characterised in that: the Raman wavelength (25) is longer than the signal wavelength (19); the beam delivery system (91) attenuates the laser radiation (13) at the signal wavelength (19) such that the power of the laser radiation (13) emitted by the laser (1) is more than the power of the laser radiation (13) at the output port (92); th

Abstract: A method and apparatus to suppress stray light refection in enclosures of optical trains are presented. Unlike prior-art that relies on absorption to suppress stray light the presented invention relies on reflections in a tapered enclosure to prevent stray light from reaching the sensor. The presented invention also provides a method to reshape the tapered enclosure into more convenient shapes using Fresnel Design. The presented invention can be realized in different ways including but not limited to (1) a monolithic enclosure, (2) a modular enclosure that can adapt to different lenses and or sensors, (3) a sleeve to be inserted into existing enclosure to enhance their performance.

Abstract: A laser amplifier module having an enclosure includes an input window, a mirror optically coupled to the input window and disposed in a first plane, and a first amplifier head disposed along an optical amplification path adjacent a first end of the enclosure. The laser amplifier module also includes a second amplifier head disposed along the optical amplification path adjacent a second end of the enclosure and a cavity mirror disposed along the optical amplification path.

Abstract: An example laser system includes a laser, a plurality of pulse stretchers coupled together in series, a pulse amplifier, a feedback module, and a lens assembly. The plurality of pulse stretchers is configured to stretch pulse widths of the laser pulses and output stretched laser pulses. The pulse amplifier is positioned between a first pulse stretcher and a second pulse stretch of the plurality of pulse stretchers, and is configured to amplify the laser pulses. The feedback module includes a pulse delay comparator configured to compare a first laser pulse of the laser pulses to a corresponding first stretched laser pulse of the stretched laser pulses. The feedback module also includes a computing device configured to determine an adjustment to a pulse stretcher of the plurality of pulse stretchers, and apply the adjustment to the pulse stretcher so as to modify a shape of a second stretched laser pulse.

Abstract: Provided are a control method and system for a cascade hybrid amplifier, in which respective hybrid amplifiers in the cascade hybrid amplifier simultaneously start to implement a pump-starting process comprising: when the hybrid amplifier receives a request to start pumping, determining whether conditions are satisfied, if yes, determining stability of power of an input light of a Raman, starting pumping of an EDFA so that the EDFA enters into an APC operation mode; starting pumping of the Raman, and calculating a gain deviation according to the calculated input light powers before and after pump-starting of the Raman when no reflection alarm exists; and adjusting gain of the Raman according to the gain deviation, and switching to an AGC (automatic gain control) operation mode after the adjustment; and switching the EDFA to the AGC operation mode.

Abstract: A specialized, dispersion-controlled fiber is particularly configured to exhibit a relatively uniform dispersion (D) over a broad spectral range (for example, 1000 nm to 2000 nm). The specialized fiber exhibits an essentially constant attenuation (?) over this same spectral range so that the fiber is defined as having a high “figure of merit” (FoM) where FoM is defined as |D|/?. The specialized fiber is well-suited for use as a pulse stretcher, providing the ability to separate out wavelength constituents of an extremely short (fs, ps) broadband pulse into the ns range, for example.

Abstract: A method and apparatus for removing free carriers from a waveguide using a p type semiconductor and an n type semiconductor connected by a short.

Abstract: A transmission apparatus includes a demultiplexer configured to demultiplex a multiplexed signal including wavelength multiplexed signals having individual wavelength bands into a wavelength multiplexed signal for each of the wavelength bands, a detector configured to detect a power value of each of the wavelength multiplexed signals for each of the wavelength bands, first compensators configured to compensate for a tilt in the wavelength multiplexed signal based on the power value for each of the wavelength bands, second compensators configured to compensate for a power of the wavelength multiplexed signal for each of the wavelength bands so as to reduce a power difference among wavelength multiplexed signals after the tilt compensation based on the power value for each of the wavelength bands, and a multiplexer configured to multiplex each of the wavelength multiplexed signals after the power compensation and output a multiplexed signal.

Abstract: An optical system for controlling gain modification, including a first non-linear optical element (NLE) through which an input optical signal and a first pump wavelength are transmitted to generate a first optical signal; a second NLE through which the first optical signal is amplified to generate a second optical signal; a third NLE through which the second optical signal is amplified to generate a third optical signal; a first heating element coupled to the second NLE to adjust a temperature of the second NLE to control a first gain profile of the second optical signal; a second heating element coupled to the third NLE to adjust a temperature of the third NLE to control a second gain profile of the third optical signal, wherein the temperatures of the second and the third NLE minimize a gain modulation of the optical system based on the first and the second gain profiles.

Abstract: A hybrid distributed amplification method based on a random fiber laser generated within erbium fiber with low doping concentration, i.e. weak erbium-doped fiber (WEDF), which includes: Step 1. constructing a fiber link via WEDF; Step 2. generating the random fiber laser based on the fiber link, the pump source, the wavelength division multiplexer and the strong feedback module; Step 3. constructing the spatial equalized gain based on hybrid gain of the erbium fiber and random fiber laser; Step 4. the signal is amplified by the hybrid spatial equalized gain. The present invention solves the typical problem of high laser threshold and low pump conversion efficiency when conventional fiber is used to generate random fiber laser for distributed amplification.

Abstract: A laser amplifier module having an enclosure includes an input window, a mirror optically coupled to the input window and disposed in a first plane, and a first amplifier head disposed along an optical amplification path adjacent a first end of the enclosure. The laser amplifier module also includes a second amplifier head disposed along the optical amplification path adjacent a second end of the enclosure and a cavity mirror disposed along the optical amplification path.

Abstract: A device for the generation of supercontinuum in infrared fiber with a compact light source comprising a microchip laser is launched directly into an infrared fiber without a nonlinear element. Light from the laser is beyond the two-photon absorption of the infrared fiber. The broadband output has a bandwidth greater than the input laser bandwidth by at least 100% and an emission wavelength range from 2 to 14 micrometers.

Abstract: An apparatus includes a remote optically pumped amplifier (ROPA). The ROPA includes a bypass filter configured to receive an optical signal and first pump power and to separate the optical signal and the first pump power. The ROPA also includes an amplifier configured to receive the optical signal from the bypass filter and to amplify the optical signal. The ROPA further includes an optical combiner/multiplexer configured to receive the first pump power from the bypass filter, receive at least second and third pump powers, combine at least two of the first, second and third pump powers, and provide different pump powers or combinations of pump powers to different locations within the ROPA to feed the amplifier.

Abstract: Methods, systems, and apparatus for phase-sensitive regeneration of a signal without a phase-locked loop and using Brillouin amplification. The system for phase-sensitive regeneration includes a data channel, one or more pumps and a mixing stage. The one or more pumps are coupled with the data channel. The mixing stage is coupled with the data channel and is for processing a data signal that is combined with an output of the one or more pumps and idler or higher harmonic. The mixing stage is configured to amplify the idler or higher harmonic using Brillouin amplification in a Brillouin gain medium to keep the one or more pumps and the data channel phase-locked.

Abstract: A Raman pump system for a Raman amplifier includes a plurality of primary Raman pumps each at a corresponding wavelength; and at least one pair of redundant Raman pumps including a primary redundant Raman pump at a primary wavelength and a secondary redundant Raman pump at a secondary wavelength, wherein only one of the primary redundant Raman pump and the secondary redundant Raman pump is employed based on a zero dispersion wavelength location of a fiber over which the Raman pump system operates. The secondary wavelength can be separated from the primary wavelength by at least 2 nm or 3 nm and no more than 10 nm. The Raman pump system can provide amplification across both the C Band and the L Band.

Abstract: The embedded apparatus disclosed herein may measure reflection coefficient values associated with back reflections in a fiber optics transmission system during a variable detection window to detect normal conditions, simulated Brillouin scattering (SBS), or excessive back reflections triggering remedial action. For example, the back reflections may indicate normal conditions if the reflection coefficients measured during an entire detection window remained below a threshold or a maximum reflection coefficient observed therein was below the threshold. Alternatively, the back reflections may trigger remedial action if the reflection coefficients measured in the entire detection window exceeded the threshold or a minimum reflection coefficient observed therein was above the threshold.

Abstract: A transmitter generates a frequency-modulated CW light so as to transmit it to a path. A receiver receives the CW light that has passed through passband filters included in the path. The receiver includes a processor. The processor measures an optical power of the received CW light every time a center frequency of the CW light is changed and transmitted by the transmitter. The processor calculates transmission characteristics of the CW light that has passed through the passband filters, on the basis of an average value of the optical power that corresponds to a center frequency of the CW light and on the basis of an amplitude component that indicates an amount of change in the optical power, the average value and the amplitude component being obtained as a result of the measurement.

Abstract: In an optical network system: control light is generated by optical modulation based on a modulated data signal which is generated by modulation of a carrier signal with a data signal; and the control light is optically combined with an optical carrier which is to propagate through a nonlinear optical medium, so as to cause cross phase modulation of the optical carrier with the control light in the nonlinear optical medium.

Abstract: The present application describes a method for controlling an output of a laser apparatus. The method includes a step of receiving, at the first multiplexer, an initial wavelength from a pump. The method also includes a step of receiving first and second seed wavelengths from a first and a second seed source, respectively. The method also includes a step of sending an output of the combiner to a first fiber. The method includes a step of combining, at a second multiplexer, an output of the first fiber. The method also includes a step of extracting the initial wavelength with the second multiplexer. Further, the method includes a step of sending the first and seed wavelengths to a second fiber.

Abstract: Methods and systems are disclosed which allow testing essential performance parameters of broadband communications systems, while using test channels of lower bandwidth, allowing thus lower cost hardware (or use of legacy test system). In particular, the methods and systems allow testing of EVM in digital systems, especially OFDM systems. The methods and systems readily apply to test equipment for production lines, such as IC testers of final product testers.

Abstract: A Raman pumping arrangement for amplifying a data optical signal (40) has a Raman pump (12) for generating a Raman pump signal (44;45), an optical supervisory channel receiver (14) for receiving an optical supervisory channel signal (42) an amplification fiber (15) arranged such that the data optical signal (40), the optical supervisory channel signal (42), and the Raman pump signal (44;45) are transmitted therethrough; and a control unit (13) configured for controlling the operation of the Raman pump (12); wherein the control unit (13) is configured for setting the Raman pump (12) in an operation mode or a start-up mode; wherein in the operation mode, the Raman pump (12) provides an operation pumping power (120), and wherein in the start-up mode, the Raman pump (12) provides a start-up pumping power (122).

Abstract: The present invention provides a fiber-cut detection method, apparatus, and system. When a fiber cut occurs, power of input signal light decreases quickly at a fiber-cut location. When the fiber-cut location is relatively far away from an amplifier, pump light consumption of the input signal light in the remaining fiber reduces due to reduction of the input signal light, which causes an increase of remaining pump optical power in the fiber and an increase of an actual gain value of the amplifier. A gain-locking function of the amplifier works, which decreases pump power of the pump light and maintains a gain of the amplifier unchanged basically. Output optical power of the amplifier decreases quickly with decrease of input optical power, and when power of an output optical signal decreases to power that is lower than preset power of the output optical signal, it is determined that a fiber cut occurs.

Abstract: A method and a system is provided for configuring a device for correcting the effect of a medium on a light signal having propagated through the medium, the device including at least one optical element whose phase profiles are individually adjustable. The configuring system and method include propagating a reference signal and a disordered signal obtained at the output of the medium through the correcting device. An interference parameter is measured and optimized by modifying the phase profile of each of the optical elements of the correcting device. A method and a system is also provided for correcting the effect of a medium on a light signal having propagated through the medium.