51 results about "Cross gain modulation" patented technology

The present invention relates to a method of embodying all-optical XOR logic gate by using semiconductor optical amplifier, and more particularly, to a technique to embody all-optical XOR logic gate utilizing the cross-gain modulation (XGM) characteristic of semiconductor optical amplifiers controllable with input currents, illumination signal, and pumping signal. The method of all-optical XOR logic element in accordance with the present invention is characterized to obtain operational characteristic of the all-optical XOR logic element by inputting pump-signal and illumination signal concurrently into two semiconductor optical amplifiers and then summing the two output signals having XGM characteristic arising from gain saturation and wavelength conversion of the semiconductor optical amplifiers.

Provided are a semiconductor optical amplifier and an optical signal processing method using the same. The reflective semiconductor optical amplifier includes: an optical signal amplification region operating to allow a downward optical signal incident from the external to obtain a gain; and an optical signal modulation region connected to the optical signal amplification region and generating a modulated optical signal. The downward optical signal is amplified through a cross gain modulation using the modulated optical signal and is outputted as an upward optical signal.

Provided are a semiconductor optical amplifier and an optical signal processing method using the same. The reflective semiconductor optical amplifier includes: an optical signal amplification region operating to allow a downward optical signal incident from the external to obtain a gain; and an optical signal modulation region connected to the optical signal amplification region and generating a modulated optical signal. The downward optical signal is amplified through a cross gain modulation using the modulated optical signal and is outputted as an upward optical signal.

The cascading structure is as following: CW light and signal light A are connected to the input end of the first coupler respectively; the output of the first coupler is connected to the first optical amplifier of semiconductor, first wavelength selector, and first power regulating device; signal light B is connected to the input end of the second coupler; output end of first power regulating device and output end of second power regulating device are connected to the input end of the second coupler; the output end of the second coupler is connected to second optical amplifier of semiconductor, second wavelength selector in sequence; through adjusting output powers of first power regulating device and second power regulating device can obtain full optical logic AND gate and / or NOT gate at different output wavelengths of the second wavelength selector. The invention realizes advantages of full optical logic device in crossed gain modulation type, and based on same class of structure.

The invention discloses an all optical quantizing encoder based on nonlinear polarization rotation effects in semiconductor optical amplifiers (SOA), which belongs to the technical field of optical communication networks and mainly comprises a power allocation unit and a quantizing encoding unit based on the nonlinear polarization rotation effects in the SOAs, wherein the quantizing encoding unit mainly comprises an initial quantizing encoding module and a gain dynamic compensation module; the action of the initial quantizing encoding module is to carry out initial quantizing encoding on sampled optical pulses; and the action of the gain dynamic compensation module is to carry out gain dynamic compensation on the pulses on which the initial quantizing encoding is finished. The all optical quantizing encoder based on the nonlinear polarization rotation effects in the SOAs is capable of solving the problems that the quantizing encoder based on cross gain modulation in the SOAs is not capable of realizing high-resolution encoding and uniform quantization, and the number of the required SOAs is excessive, thereby, the all optical quantizing encoder based on the nonlinear polarization rotation effects in the SOAs has the advantages that the resolution is high, the quantization is uniform, and the number of the required SOAs is less, and simultaneously, the quantizing encoder also has the advantages of low energy consumption and convenience in photon integration and is a key technology of realizing all optical networks in future.

The present invention relates to an apparatus and a method for realizing all-optical NOR logic device using the gain saturation characteristics of a semiconductor optical amplifier(SOA). More particularly, the invention relates to a 10 Gbit / s all-optical NOR logic device among all-optical logic devices, in which a signal transmitted from a given point of an optical circuit such as an optical computing circuit is used as a pump signal and a probe signal.The method for realizing an all-optical NOR logic device using the gain saturation characteristics of the SOA according to the present invention comprises the steps of: utilizing A+B signal which couples together an input signal pattern A (1100) and an input signal pattern B (0110) as a pump signal (1110); utilizing a probe signal (1111) by generating a clock signal out of said input signal pattern A (1100); and obtaining a Boolean equation {overscore (A+B)} by making said probe signal and said pump signal incident upon the SOA simultaneously from the opposite direction.The all-optical logic device according to the present invention has a simple construction since it is realized through the XGM (Cross Gain Modulation) method which utilizes the gain saturation characteristics. Also, it is expected that the method employed in the present invention could be used for realizing other all-optical logic circuits and devices.

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.

The invention provides an all optical wavelength converter and all optical wavelength conversion method for a dual-semiconductor optical amplifier structure and relates to a hybrid wavelength division time division multiplex passive optical network system. A downlink signal light can be divided into two paths through a 1:2 optical splitter, i.e., one path of light is compensated by an erbium-doped fiber amplifier (EDFA), combined by a wavelength division multiplexer and then sent to a user terminal; the other path of light successively passes through the EDFA, a first semiconductor optical amplifier and an adjustable optical attenuator and then is used for the probe light input of a cross-gain modulation structure; after being divided by the wavelength division multiplexer, an uplink signal light is successively connected with the EDFA, the adjustable optical attenuator and a polarization controller and is used for the pump light input of the cross-gain modulation structure; and the probe light and the pump light can be input into an optical coupler, converted through a second semiconductor optical amplifier and a band pass filter and then output. The all optical wavelength converter and the all optical wavelength conversion method are in accordance with the optical passive and colorless requirements; and meanwhile, the all optical wavelength converter has a simple system structure, thus reducing the operation and maintenance costs of the system and being beneficial to the application and later maintenance for large-scale projects.

A method and system for compensating for side effects of cross gain modulation in amplified optical networks, which allows reliable identification of expected and unexpected channels in the network is provided. Each optical channel traveling in the optical network is marked with a unique channel signature (expected channel signature), having one or more dither tone modulated onto the optical channel; followed by detecting a spectrum of tones, including said modulated dither tones and ghost tones thereof produced by the cross gain modulation in the optical network, at various locations in the optical network. Amplitudes of the spectrum tones, which belong to the expected channel signature, are compared with a first threshold, while amplitudes of the remaining spectrum tones, which are not the valid tones, are compared with a second threshold, which is lower than the first threshold. The spectrum tones are identified as valid tones if their amplitudes are above the first threshold; and an alarm signaling that the expected channel signature is missing is generated if the amplitude of the spectrum tone is below the first threshold. Yet another alarm is generated signaling that an unexpected channel is detected in the network if the amplitude of at least one of the remaining spectrum tones is exceeding the second threshold. Alternatively, the other alarm is generated if amplitudes of the remaining spectrum tones belonging to one of the allowable channel signatures in the network are above the second threshold. A corresponding system incorporating the step of the methods described above is also provided.

The invention discloses an all-optical wavelength conversion integrated chip based on transient chirp jump and belongs to the field of photoelectron. The integrated chip comprises a semiconductor optical amplifier, an array waveguide grating and a delay interferometer, wherein the semiconductor optical amplifier, the array waveguide grating and the delay interferometer are connected sequentially and are integrated on a same semiconductor substrate, thereby forming a chip; an input end of the semiconductor optical amplifier is connected with an optical power coupler through an optical fiber; the delay interferometer is connected with the optical fiber; and the optical fiber is arranged at an output end of the integrated chip. According to the all-optical wavelength conversion integrated chip based on the transient chirp jump, a crossing gain modulating effect of the semiconductor optical amplifier is utilized to modulate a signal on pump light to detecting light different in wavelength; under the blue shift filtering action of the array waveguide grating, an ultrafast transient chirp jump dynamic process is extracted; the limitation of slower gain recovery time of the semiconductor optical amplifier to the operating rate is overcome; the speed of wavelength conversion is increased; the integrated chip has the characteristics of high wavelength conversion speed, small volume, easiness in integrating, and the like; the size of the whole all-optical wavelength conversion integrated chip can be reduced to 4.5mm*2mm; and the all-optical wavelength conversion integrated chip can be applied to a routing system of the next generation optical network.

The invention relates to a high-speed all-optical wavelength conversion integrated device and belongs to the technical field of photoelectron. The integrated high-speed all-optical wavelength conversion device mainly comprises a cascaded structure of two semiconductor optical amplifiers and an electroabsorption modulator. By utilizing a cross-gain modulation effect in a first semiconductor optical amplifier, a signal on pumping light is modulated onto detecting light with a different wavelength; by utilizing an electroabsorption effect of the electroabsorption modulator, the pumping light is filtered; and by utilizing a self-gain effect of a second semiconductor optical amplifier, a pattern effect of outputting an optical signal in the high-speed wavelength conversion process is compensated, so that the high-speed all-optical wavelength conversion is realized. In the invention, the electroabsorption modulator is used in the all-optical wavelength conversion device for realizing a filtering function for the first time. When completing the high-speed all-optical wavelength conversion, the integrated high-speed all-optical wavelength conversion device has the characteristics of small size and easiness for integration and can be applied to a routing technology of the next generation of optical network.

The present invention relates to a method of embodying all-optical XOR logic gate by using semiconductor optical amplifier, and more particularly, to a technique to embody all-optical XOR logic gate utilizing the cross-gain modulation (XGM) characteristic of semiconductor optical amplifiers controllable with input currents, illumination signal, and pumping signal.The method of all-optical XOR logic element in accordance with the present invention is characterized to obtain operational characteristic of the all-optical XOR logic element by inputting pump-signal and illumination signal concurrently into two semiconductor optical amplifiers and then summing the two output signals having XGM characteristic arising from gain saturation and wavelength conversion of the semiconductor optical amplifiers.

A phase optimization apparatus and method to obtain a maximum extinction ratio by feeding back a portion of an optical signal output from a Mach-Zehnder interferometer wavelength converter using XPM of a semiconductor optical amplifier to maintain an optimum phase difference between two arms. The phase optimization apparatus includes a first arm having a first semiconductor optical amplifier that amplifies a pump signal and a probe signal, a second arm having a second semiconductor optical amplifier that amplifies the probe signal, and a π phase shifter that controls the phase of the amplified signal, an optical band-pass filter that filters optical signals to output only the modulated probe signal; and a phase control unit that receives feedback to output to the π phase shifter of the second arm a phase control signal, which controls a phase difference between the first and second arms.

An optical signal amplification device for outputting an output signal light which has the same wavelength as an input signal light and an intensity variation identical in phase with an intensity variation of the input signal light. The device includes: (a) an amplifying element having a cross gain modulation function of outputting an output light including (i) the output signal light and (ii) a neighboring light which has a neighboring wavelength different from the wavelength of the output signal light and an intensity variation inverted in phase with respect to the intensity variation of the output signal light; (b) inputting means for inputting the input signal light to the amplifying element; (c) a selecting element extracting the output signal light and at least a part of the neighboring light from the output light, such that the extracted output signal light and neighboring light are separated from each other; and (d) feedback means for feeding back the neighboring light extracted by the selecting element, to the amplifying element, so that the neighboring light is inputted to the amplifying element, for rendering the amplifying element to generate a negative feedback amplification effect.

The present invention provides a wavelength converting apparatus and optical cross connect system using the same. The wavelength converting apparatus includes a plurality of optical sources of fixed wavelengths, a switching means, and at least one wavelength converting means. The optical sources with fixed wavelengths provide probe beams with fixed wavelengths, the wavelength being different from each other. The switching means selects at least one beam of a wavelength corresponding to a wavelength conversion request of a transmission signal among a plurality of beams inputted from the fixed-wavelength light sources, and provides the selected beam as a probe beam. The wavelength converting means receives the transmission signal and the probe beam from the switching means, and converts a wavelength of the inputted transmission signal through cross gain modulation, cross phase modulation or optical-to-electrical-to-optical (O / E / O) conversion of the transmission signals and the probe beams.

A technique for generating variable pulse delays uses one or more nonlinear-optical processes such as cross-phase modulation, cross-gain modulation, self-phase modulation, four-wave mixing or parametric mixing, combined with group-velocity dispersion. The delay is controllable by changing the wavelength and / or power of a control laser. The delay is generated by introducing a controllable wavelength shift to a pulse of light, propagating the pulse through a material or an optical component that generates a wavelength dependent time delay, and wavelength shifting again to return the pulse to its original wavelength.

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.

The invention discloses an all-optical phase modulator which comprises a differential balance signal forming unit and an optical phase modulation unit. The optical phase modulation unit comprises a semiconductor optical amplifier; the differential balance signal forming unit is used for changing an intensity-modulated optical signal with a wavelength of lambda 1 into two paths of differential balance signals, and the two paths of differential balance signals are injected into the semiconductor optical amplifier respectively in the same direction with probe light and in a different direction with the probe light; the two paths of differential balance signals respectively are a first path of optical signal with the wavelength of lambda 1 and a second path of optical signal with a wavelength of lambda' 1 after radix-minus-one complement; the first path of optical signal and the second path of optical signal after radix-minus-one complement are reverse codes mutually; and the semiconductor optical amplifier is used for generating cross phase modulation according to interaction of two paths of differential balance signals and the probe light which needs to be modulated. The all-optical phase modulator disclosed by the invention can implement rapid tuning, and is simple in structure and convenient to use.

The invention relates to the field of photoelectric technology and discloses a width-adjustable full-light optical switch of a switch window. The full-light optical switch uses cross gain modulation XPM effect of a semiconductor optical amplifier (SOA) for changing the offset of the SOA in a nonlinear optical loop mirror (NOLM) by controlling the delay time of an optical delay line (ODL) in the NOLM, so that the problems that the width of the optical switch is unadjustable, the flexibility of the optical switch is small and the like, the width of the optical switch is adjustable, and the operation is convenient and flexible.

The invention provides a full gloss burst amplifier based on the SOA cross gain modulation effect, which comprises a laser, an optical combiner, an SOA, an EDFA and an optical filter, wherein a burst signal is input and a local continuous control signal is input to the SOA, the control signal is converted to the burst signal relatively complemented with the original input signal because of the SOA cross gain modulation effect, so the total power of the control signal and the burst signal is changed to be basically constant, the mixed signal is input to the EDFA for amplifying, and the transient effect of the EDFA can be greatly restrained, thereby the burst signal without anamorphic magnification can be obtained after the mixed signal is filtered by the optical filter. The invention can be applied to the amplification of the optical burst signal in the optical fibre network and the restraining of the transient effect of the EDFA.

A dark pulse fiber laser consists of a semiconductor optical amplifier, an optical circulator, a band-pass filter, a single-mode fiber, a 50:50 coupler, a 20:80 coupler, an optical isolator and a polarization controller which are connected to one another through optical fibers so as to form two closed loops. By the dark pulse fiber laser, laser light in a resonant cavity is subjected to cross gain modulation and cross phase modulation through fed back laser light, and dark pulses can be generated. The dark pulse fiber laser has the advantages that the dark pulse fiber laser is simple in structure and low in cost, a pulse width tuning range is large, the dark pulse fiber laser can work at normal temperature, and the application prospect on the aspect of signal processing is high.

The invention relates to an all-optical multicast optical switch system. A control signal is continuous light with different wavelengths and is reversely input into an SOA-XGM wavelength converter; one part of input signal light enters the wavelength converter, is reversely converted onto control light through cross-gain modulation, and is output in a corresponding second-stage SOA-XGM wavelength converter through a wavelength routing module; the other part of the input signal light is changed into the continuous light through a traveling wave semi-conductor optical amplifier and input into a 1 multiplied by N coupler through an optical isolator, each output end of the 1 multiplied by N coupler is respectively connected with a corresponding second-stage SOA-XGM wavelength converter; in the second-stage wavelength converter, the information on the control light is reversely converted onto the wavelength of the signal light again through the cross-gain modulation, the output of the second-stage wavelength converter is the output of the all-optical multicast optical switch system. The all-optical multicast optical switch system solves the problem of optical signal multicast in the optical switch system by taking advantage of two times of wavelength transformations and the gain saturation of the SOA.

Wavelength converter and methods are based on cross-gain modulation. The wavelength converter has two semiconductor optical amplifiers to perform double cross-gain modulations and double inversions. The first semiconductor optical amplifier performs a first cross-gain modulation on a first continuous wave light using the input light as a modulating light to generate an inverted first-stage cross-gain modulated light. The second semiconductor optical amplifier performs a second cross-gain modulation on a second continuous wave light using the first-stage cross-gain modulated light as a modulating light to generate a double-inverted output light. The output light is non-inverted with respect to the input light.

The invention discloses an optical label and payload separator based on a quantum dot semiconductor optical amplifier (QDSOA). On one hand, by means of high pass characteristics of saturated QDSOA, a low-frequency optical label in an optical packet is filtered (repressed) to obtain a payload signal that is to say erasing the optical label; on the other hand, by means of cross gain modulation of the QDSOA, continuous fill-in light with wave length of lambda 2 is input, and the continuous fill-in light is modulated to an inversion signal of the optical packet to obtain an optical label signal of which payload is repressed; finally, demultiplexing is performed through wavelength division multiplexers to separate the optical label and the payload. An experiment shows that the separation of the optical label from the payload is correctly achieved by the optical label and payload separator, the suppression ratio of the separated label and payload is high, and the eye pattern opening degree is good. According to the optical label and payload separator based on the QDSOA, the structure uses the QDSOA as the center, one semiconductor laser and two wavelength division multiplexers are added to finish separation, the structure is simple, meanwhile, the separation is based on modulation frequency of the optical label and the payload, and thereby, influence of time sequence accuracy on separation can be avoided.

An optical communication system transmitting a plurality of channel wavelengths is provided. The system includes a transmitter unit, a receiver unit, and an optical transmission path interconnecting the transmitter and receiver units. The transmission path has a concatonation of optical fibers defining a dispersion map such that each of the channel wavelengths are located at FMX and XPM antiresonances at which FWM and XPM are suppressed.

The invention discloses an on-chip integrated all-optical neural network optical computing chip, and the chip comprises a multi-amplitude pulse light source module which comprises at least two lasers and is used for generating a multi-amplitude optical computing input pulse signal; the cross gain modulation module comprises a Mach-Zehnder interferometer SOA-MZI module based on a semiconductor optical amplifier and a semiconductor optical amplifier SOA module, and is used for carrying out wavelength conversion on a multi-amplitude optical calculation input pulse signal according to a nonlinear activation Sigmoid function based on cross gain modulation of the SOA-MZI module and the SOA module; a pulse optical signal with a balanced amplitude is output; the threshold value adjusting module is used for adjusting the saturation state of the SOA in the SOA-MZI module and the SOA module so as to adjust the threshold value of the Sigmoid function; and the photonic integrated chip substrate is used as a chip substrate of the all-optical neural network optical computing chip. The all-optical monolithic integration technology is adopted, and high-speed, low-power-consumption, low-cost and high-integration-level neural network optical calculation of a chip-level all-optical structure is achieved.

The present invention relates to the microwave signal generation technology field, especially to a tunable optoelectronic oscillator based on cross phase modulation. The tunable optoelectronic oscillator based on cross phase modulation comprises a narrow linewidth laser; light output by a high-power narrow linewidth laser passes through a dual-drive electrooptic intensity modulator, an optical coupler 1, a Mach-Zehnder interferometer and a non-linear fiber loop mirror in order; the Mach-Zehnder interferometer is formed by an optical coupler 2 and an optical coupler 3; the non-linear fiber loop mirror is formed by a wavelength division multiplexer, a high-nonlinear fiber and an optical coupler 4; light output by the optical coupler 3 passes through a photoelectric detector, an amplifier, a band-pass filter, a 10dB coupler and a 3dB bridge; and the 3dB bridge is connected with the dual-drive electrooptic intensity modulator to form an annular resonator. The tunable optoelectronic oscillator based on cross phase modulation also comprises control light, and the control light enters the wavelength division multiplexer through an erbium-doped optical fiber amplifier and a polarization controller in order and enters the non-linear fiber loop mirror through the wavelength division multiplexer.

The invention discloses an instantaneous microwave frequency measurement device and method based on dispersion Fourier transform, which belong to the technical field of microwave photons, and are mainly applied to measurement of instantaneous microwave signal frequency. The device comprises an ultra-short pulse light source, a dispersion Fourier transform module I, an electro-optical intensity modulator, an optical power divider, a dispersion Fourier transform module II, a nonlinear photon mixing module, a photoelectric detector I, a photoelectric detector II, a microwave power coupler and a spectrum analysis module. The dispersion Fourier transform modules are dispersion mediums, can be single-mode fibers or fiber Bragg gratings, and are used for realizing optical pulse width stretching and broadening of the ultra-short pulse light source. The nonlinear photon frequency mixing module realizes photon frequency mixing by utilizing nonlinear effects such as a cross gain modulation effectand a four-wave frequency mixing effect, and can be a high nonlinear optical fiber or a nonlinear semiconductor optical amplifier. The device and the method have the advantages of instantaneity, multi-tone, broadband, high precision and no blind area frequency measurement.