171 results about "Injection locking" patented technology

A dual-injection locked frequency dividing circuit is proposed, which is designed for integration to a gigahertz signal processing circuit system for providing a frequency dividing function to gigahertz signals. The proposed circuit architecture is characterized by the provision of a dual-injection interface module on the input end for dividing the input signal into two parts for use as two injection signals, wherein the first injection signal is rendered in the form of a voltage signal and injected through a direct injection manner to the internal oscillation circuitry, while the second injection signal is rendered in the form of an electrical current and injected through a resonant circuit to the internal oscillation circuitry. This feature allow the proposed frequency dividing circuit to have broad frequency locking range and low power consumption.

Aspects of the disclosure relate generally to a circuit for sustaining an radio frequency (RF) modulated optical signal. The circuit may comprise a self injection locking component having a fiber optic delay line over which a portion of the optical signal propagates. The circuit may also comprise a self phase locked loop component having at least two fiber optic cables having different lengths and over which another portion of the optical signal propagates and a phase detector coupled to the at least two fiber optic cables and configured to determine a phase difference between the signals propagating over one of the respective fiber optic cables. The circuit may further comprise a voltage controlled oscillator configured to generate a stable oscillating signal in response to signals generated by each of the self injection locking and self phase locked loop components, the stable oscillating signal being configured to sustain the optical signal.

Disclosed are a wavelength division multiplexing-passive optical network (WDM-PON) system using self-injection locking, an optical line terminal thereof, and a data transmission method. A wavelength division multiplexing-passive optical network (WDM-PON) system according to an aspect of the invention includes an optical line terminal. The optical line terminal includes a reflector that is installed at the input side of a multiplexer and reflects an optical signal having a predetermined wavelength, and a light source that generates a multimode optical signal to transmit the generated multimode optical signal to the multiplexer through the reflector, receives reflected light by the reflector, and oscillates at a wavelength of the received reflected light. According to the aspect of the invention, it is not necessary to separately control the temperature of a light source for a downstream signal, and stable communication can be performed by collectively controlling wavelengths of downstream channel optical signals for downstream channels through temperature control of the multiplexer.

A wavelength division multiplexed-passive optical network includes an optical line terminal for generating downstream optical signals of discrete wavelengths and for receiving upstream optical signals of discrete wavelengths, a remote node, coupled to the optical line terminal, a wavelength division unit settled to reflect a predetermined wavelength, and a plurality of optical network units. Each optical network unit has an optical source which is oscillated in a multi-mode and is self-injection locked by the predetermined wavelength provided thereto, thereby to generate the upstream optical signal in a single mode to be provided to the remote node.

The present invention relates to a metal nozzle boss provided with a sealing device, which has highly improved tightness and is combined with a plastic liner of a composite vessel used as a high-pressure vessel. The metal nozzle boss uses an elastic seal ring and a tightening piece in the plastic liner, so that the nozzle boss reliably seals the junction of the nozzle boss and the liner and prevents gas leakage from the vessel. The blade part of the nozzle boss has a dovetail-shaped locking groove, with locking ridges formed in the locking groove. Thus, when the plastic liner is produced by injecting molten resin into the locking groove, the plastic liner is securely combined with the metal nozzle boss. The composite vessel having the metal nozzle boss can be used as a fuel tank for natural gas vehicles or a hydrogen tank for fuel cell vehicles.

The invention discloses an active optical phased array photon integration chip and a manufacturing method thereof. The chip comprises a coherent laser array, an optical phase modulator array, a transitional waveguide array and a light field radiation array, wherein the coherent laser array is a master-slave laser realized through a same material and a same technology; through a unidirectional injection locking mode, a plurality of slave lasers possess a same frequency and good coherence of a fixed phase; the optical phase modulator array controls phase delay of each optical phase modulator in the plurality of optical phase modulators to light through an electric signal modulation mode; and the transitional waveguide array and the light field radiation array are used for adjusting wave beams and emission positions of coherent beams which are emitted from different lasers, pass through different optical phase modulators and possess different optical phase delays and determining a coherent superposed light beam emitting direction according to differences of the phase delays. The integration chip can be integrated on a same substrate. Total power of output light is formed by coherent superposition of slave lasers. And the chip possesses advantages of chip integration and high emitting power.

A polar receiver using injection-locking technique includes an antenna, a first filter, a first voltage-controlled oscillator, a first mixer, a frequency discriminator, a second filter, a third filter, a first analog-digital converter, a second analog-digital converter and a digital signal processing unit. Mentioned polar receiver enables to separate an envelope signal and a frequency-modulated signal from a radio frequency signal received from the antenna via the injection locking technique of the first voltage-controlled oscillator and the frequency discriminator. The envelope component and the frequency-modulated component can be digitally processed by the digital signal processing unit to accomplish polar demodulation.

A quadrature oscillator includes a master tuned oscillator and two injection-locked slave tuned oscillators.

The present invention relates to an RF integrated circuit comprising a frequency synthesizer and a QAM modulator for modulating a baseband signal of frequency FBB, the frequency synthesizer supplying to the QAM modulator an output signal of frequency F1 adjustable with a frequency step ΔF1, for forming a carrier signal of the QAM modulator. According to the present invention, the frequency synthesizer is a Vernier effect frequency synthesizer comprising an auxiliary frequency synthesizer supplying an auxiliary signal of frequency F2 adjustable with a frequency step ΔF2 and a main frequency synthesizer having a phase-locked loop bandwidth at least two times higher than the frequency step ΔF2 of the auxiliary signal.

The invention discloses a compensator and compensation method for transmission delay in optical fiber time frequency transmission. The compensator comprises a central station and a remote terminal, wherein the central station is connected with the remote terminal through optical fibers, the central station comprises a time frequency scale source, a frequency multiplier I, a frequency multiplier II, a filter I, a frequency mixer I, a frequency mixer II, a filter II, a light emitting module I, a combiner, a light receiving module I and an amplifier I, and the remote terminal comprises a wave separator, an optical modulator I, an optical modulator II, a light receiving module II, an amplifier II, a filter III, a phase shifter, a power divider, a light emitting module II and an electrical interface. The compensation method includes the steps that the central station conducts long-distance injection locking on a photoelectric oscillator of the remote terminal, the remote terminal accumulates errors and transmits the errors back to the central station, the central station conducts compensation through phase delay and a fluctuation regulation and control circuit, and therefore the output of the photoelectric oscillator of the remote terminal is locked to the central station. According to the compensator and the compensation method, the asymmetry of two-way delay is eliminated, therefore, the transmission accuracy can not be limited by the measurement accuracy of the system, and accurate long-distance transmission can be conducted.

Briefly, devices and methods for tuning of quadrature oscillators which may be used, for example, in a Complementary Metal-Oxide Semiconductor (CMOS) process. Devices and methods in accordance with some exemplary embodiments of the invention may allow, for example, improved locking, tuning and performance of slave oscillators and a master oscillator within a quadrature oscillator utilizing injection-locking.

Provided is a millimeter wavelength range transceiver device which can improve phase noise characteristics and which can also independently calibrate each respective local oscillator of a transmission unit and a reception unit. This millimeter wavelength range transceiver device comprises a transmission unit (10), a reception unit (20), and a reference frequency signal generator (30). The transmission unit (10) comprises a transmission-use local oscillator (11) comprising an injection-locked oscillator, a transmission-use mixer (12) for mixing the signal from the transmission-use local oscillator and a transmission baseband signal, and a transmission-use amplifier (13) for amplifying the signal from the transmission-use mixer to a transmission-use antenna (15). The reception unit (20) comprises a reception-use amplifier (25) for amplifying a signal from a reception-use antenna (24), a reception-use local oscillator (22) comprising an injection-locked oscillator, and a reception-use mixer (23) for mixing the signal from the reception-use local oscillator and the signal from the reception-use amplifier in order to output a reception baseband signal. A reference frequency signal generator (30) injects a reference frequency signal into the transmission-and-reception-use local oscillators (11 and 22).

The invention relates to a tunable erbium-doped fiber ring laser which can output stable wavelength and power, which relates to an optical fiber communication technology. The tunable laser and an isolator of the invention are connected with the ring cavity through an input terminal of a first optical coupler, the 980nm pumping is optically coupled in the erbium-doped fiber gain medium by a WDM coupler; a second optical coupler is an output terminal; through controlling phase-shift phase of phase-shifted grating, filtering function can be realized; through regulating the wavelength of the injected laser of the tunable laser, injection locking can be realized and the laser can be stably outputted. The tunable single-longitudinal erbium-doped fiber ring laser of the invention has the advantages of low cost, simple device and easy operation; the tunable single-longitudinal mode output with output wavelength and wavelength of stable power can be finally obtained.

The invention provides a high-quality tunable photoproduction microwave source based on a semiconductor double-module laser. The microwave source comprises an amplification feedback laser, a three-port optical circulator, an optical coupler, an optical fiber amplifier and a polarization controller, wherein a port 2 of the optical circulator is connected with the amplification feedback laser, a port 1 of the optical coupler is connected with a port 3 of the optical circulator, the input end of the optical fiber amplifier is connected with a port 2 of the optical coupler to enable the feedback strength to be larger than a threshold value of self-injection locking of the amplification feedback laser, the input end of the polarization controller is connected with the output end of the optical fiber amplifier, the output end of the polarization controller is connected with a port 1 of the three-port optical circulator, and the polarization controller is used for controlling the polarization state of feedback signals, injected back by a feedback circuit, of the amplification feedback laser. The microwave source can overcome the defects of the stability and the line width of the microwave signals generated by the double-module laser, the high-quality microwave source with the tunable narrow line-width can be generated without using an external microwave source as a standard, and the microwave source has the advantages of being high in integration level, compact in structure, good in stability, simple in manufacturing process, low in cost and easy to realize.

The present invention details fabrication guidelines of integrated optoelectronic oscillators with frequency and phase stability, having higher frequency selectivity in a relatively small size (compared to the larger size of a higher order electrically realized RF filter), reduced temperature sensitivity, and minimized frequency drift. The integrated photonic components and RF oscillator may use Silicon photonics and microelectronic integration using CMOS and BiCMOS technology, eliminating the need for bulky and / or discrete optical and microwave components.

Disclosed are a wavelength division multiplexing-passive optical network (WDM-PON) system using self-injection locking, an optical line terminal thereof, and a data transmission method. A wavelength division multiplexing-passive optical network (WDM-PON) system according to an aspect of the invention includes an optical line terminal. The optical line terminal includes a reflector that is installed at the input side of a multiplexer and reflects an optical signal having a predetermined wavelength, and a light source that generates a multimode optical signal to transmit the generated multimode optical signal to the multiplexer through the reflector, receives reflected light by the reflector, and oscillates at a wavelength of the received reflected light.; According to the aspect of the invention, it is not necessary to separately control the temperature of a light source for a downstream signal, and stable communication can be performed by collectively controlling wavelengths of downstream channel optical signals for downstream channels through temperature control of the multiplexer.

The invention discloses a multi-channel chaotic synchronization communication system in a simple topological structure. The output of a semiconductor laser which is operated in a chaotic state is uniformly divided into two parts, and the two parts are injected into two mutual injection lasers which are connected by n different-time-delay bidirectional optical fiber branches respectively through two same unidirectional optical fiber branches; under an injection-locking effect of unidirectional injection, stable and high-quality chaotic synchronization can be realized between the two multiple-time-delay mutual injection lasers; and accordingly, each mutual injection laser can synchronously send n pieces of information and receive n pieces of information, so that the multi-channel chaotic synchronization communication is realized. By the multi-channel chaotic synchronization communication system, the chaotic synchronization is extremely easily realized in a multiple-time-delay mutual injection system in a simple structure, and the problem that the injection and feedback are required to conform to a strict mathematical relation for realizing the synchronization in the conventional multiple-time-delay mutual injection system is solved. Moreover, the multi-channel chaotic synchronization communication system supports multi-information simultaneous bidirectional transmission between the two lasers and has a guiding significance for chaotic network communication.

The invention discloses an MDI-QKD system and an MDI-QKD method. The MDI-QKD system comprises two clients and a public measurement terminal, the public measurement terminal is provided with a master laser, the two clients are separately provided with slave lasers corresponding to the master laser, and the public measurement terminal is further provided with a detection module used for receiving optical signals from the lasers. A quantum state preparation process of the MDI-QKD system is an internal modulation process that is realized by two master and slave lasers together based on the photoinjection locking idea and has essential defense to the Trojan Horse attack. The first condition for the realization of the Trojan horse attack is that each modulation device for preparing a quantum state in a QKD system structure is independent from a light source and is an external modulation device, while no external modulation device is deployed in the quantum state preparation process of the MDI-QKD system, the quantum state preparation process is realized in the light source, and thus the realization condition of the Trojan Horse attack is damaged.

The present invention relates to an optical frequency synthesizer and an optical frequency synthesizing method using femtosecond laser optical injection locking, which inject a femtosecond laser optical frequency comb into a diode laser, thus obtaining single-mode laser light, phase-locked to only a single mode in the optical frequency comb, and which change the optical frequency and interval, that is, the repetition rate, of a femtosecond laser, together with the frequency of a semiconductor laser, thus scanning optical frequencies while realizing a single desired optical frequency. The optical frequency synthesizer using femtosecond laser optical injection locking, includes a mode-locked femtosecond laser (110), which is a master laser, and a diode laser (120), which is a slave laser and into which laser light emitted from the femtosecond laser is injected.

The present invention relates to an RF integrated circuit comprising a frequency synthesizer and a QAM modulator for modulating a baseband signal of frequency FBB, the frequency synthesizer supplying to the QAM modulator an output signal of frequency F1 adjustable with a frequency step ΔF1, for forming a carrier signal of the QAM modulator. According to the present invention, the frequency synthesizer is a Vernier effect frequency synthesizer comprising an auxiliary frequency synthesizer supplying an auxiliary signal of frequency F2 adjustable with a frequency step ΔF2 and a main frequency synthesizer having a phase-locked loop bandwidth at least two times higher than the frequency step ΔF2 of the auxiliary signal.

A CO2 laser reference oscillator (RO) can provide injection seeding to a Q-switched (QS) or Q-switched cavity dumped (QSCD) CO2 laser, where the output frequency of the RO laser is locked to the peak of the laser line by the use of appropriate electronics to dither one of the resonator mirrors of the reference oscillator. This injected radiation seeds the radiation building up within the Q-switched laser cavity, such that the oscillating frequency favors the wavelength of the injected radiation. An electronic feedback control circuit can be used to lock an axial mode of the Q-switched laser to line center. The change in build-up time of the pulses within the QS laser can be used to maintain cavity length at a value that enables oscillating at the peak of the same laser line that is injected into QS laser.

The invention discloses a device for producing frequency multiplication low noise microwave signals. The device comprises a tuned laser, a straight adjustable laser, a stabilization microwave source, a first coupler and a detector. The tuned laser is used for outputting tunable laser, a part of the tunable laser is injected to the straight adjustable laser, the straight adjustable laser is an injected and locked auxiliary laser, and the straight adjustable laser generates vertical sideband light under modulation of a low-frequency microwave signal. The stabilization microwave source is used for outputting the low-frequency microwave signal to the straight adjustable laser, the first coupler is used for outputting the other part of the tunable laser and the vertical sideband light to the detector after the other part of the tunable laser and the vertical sideband light are coupled, and the detector is used for conducting photovoltaic conversion on the tunable laser input into the detector and the vertical sideband light input into the detector so as to convert the tunable laser and the vertical sideband light into a high-frequency microwave signal. According to the scheme, a light source of the straight auxiliary adjustable laser and a light source of the tuned laser are in phase correlation through light injection, the stabilization microwave source tunes the straight adjustable auxiliary laser to generate a stable vertical sideband, and the stable multi-time frequency microwave signals which are triple than the microwave signal are generated.

The present invention relates to optical gyro, and is especially fiber laser gyro comprising fiber laser, detector and differential frequency processing circuit. It features that the fiber laser consists of semiconductor laser with tail fiber, single-frequency distributed feedback fiber laser DFB, fiber ring and fiber coupler, with the fiber ring comprising wavelength division multiplexer, isolator, gain fiber and fiber coupler. Two fiber rings with gain fiber forms two independent resonant cavities, into which the DFB injects seed laser to lock their work wavelength. The isolator makes the laser work in single-direction traveling wave state, and the laser transmission direction is clockwise in one ring and counterclockwise in the other. The present invention eliminates spatial hole burning in homogeneously expanded gain medium and interlock effect caused by back scattering, and makes laser in two ring cavities work in narrow-line width single-longitudinal mode state.

The invention relates to the optical communication technology, in particular to a method for extracting local oscillating light in a Super-channel CO-OFDM system. The local oscillating light is extracted in the Super-channel CO-OFDM system with the method that optical injection locking is combined with an optical phase-locked loop, the complexity of an optical receiver to be used for compensating for frequency offset and phases can be effectively lowered, and the power consumption, the cost and the like of the receiver can be further reduced. According to the method, as photon carriers extracted after processing such as optical injection locking and phase locking is carried out serve as the local oscillating light, the local oscillating light can be kept the same as the signal photon carriers in frequency and phase, the complexity of a digital signal processing algorithm in the coherent optical receiver can be greatly lowered, the power consumption of the digital signal processing algorithm in the coherent optical receiver can be greatly reduced, and the performance advantages, including the receiver sensitivity, the spectral efficiency and the robustness to polarization dispersion, of the CO-OFDM can be better developed. In addition, by means of the method, the CO-OFDM system can have the high operation efficiency, and reduction, caused by the frequency deviation between a local laser apparatus and a transmitting-end laser apparatus, of the coherent receiving efficiency can be effectively reduced.

The invention provides a fiber laser intensity noise suppressing device and a working method thereof. The device comprises a single mode semiconductor pump light source, a wavelength division multiplexer, a fiber resonator, a fiber coupler, a fiber isolator, a fiber circulator and a laser intensity noise suppressing device. Through a self-injection locking structure of a fiber laser, laser signals are injected into the fiber resonator after conventional intensity noise suppressing treatment, so that the finally output laser intensity noise is greatly reduced. The device with a relatively simple structure can realize high performance fiber laser output with ultralow intensity noise, thereby being of great importance for expansion of the application of fiber lasers in the field of high-precision optical fiber sensing, coherent light communication and atomic and molecular spectroscopy.

The invention discloses a self-injection locking resonant optical gyroscope and a working method thereof and belongs to the technical field of optical gyroscopes. The existing resonant optical gyroscope is complex in structure and work. LD is used as a working light source so that the size of the optical gyroscope is reduced. The two LD working light sources share a passive ring resonator so thatnon-reciprocity noise is avoided. Compared with the existing resonant optical gyroscope, the self-injection locking resonant optical gyroscope mainly comprises conventional circuit elements such as circulators, isolators, couplers and resonators in the field of optical fiber technology and has a symmetrical and simple structure. The self-injection locking frequency stabilization method is free ofa modulated signal generator and power-based frequency stabilization. Lights transmitted by the two working light sources carry out resonance along opposite directions in the same passive ring resonator, and two resonance light beams transmitted along different directions are divided through a splitting coupler and are respectively used for frequency stabilization and gyro signal detection. The optical gyroscope has a simple structure and works in a simple work mode.

A method for producing ultrashort pulses from an external injection gain-switched laser comprises the following steps: inputting an ultrashort optical pulse signal having multi-longitudinal mode spectral characteristic, produced by a gain-switched laser, into an optical amplifier to amplify it; selecting, by a spectral component signal selector, a narrow spectral component signal outputted by the optical amplifier that is within an amplified spontaneous emission noise frequency band and has a central wavelength equal to one of the longitudinal modes of the gain-switched laser; and, using one part of the narrow spectral component signal as an external seed light, which is reinjected into the gain-switched laser via a spectral component signal feedback loop so that the oscillation of a selected single longitudinal mode within a cavity of the gain-switched laser is enhanced, thereby forming external light injection locking, another part of the narrow spectral component signal being used as a required ultrashort pulse.

The present disclosure provides a dual loop self injection locked optoelectronic oscillator having a single fiber in its both loops which generates a high Q microwave output signal with a very low phase noise and spurious harmonics levels. The circuit may comprise an optical coupler having different lengths of the output arms and two electronic paths, which form two feedback loops of the oscillator. The circuit may comprise a single fiber with high Q, an optical circulator, and an optical coupler, which serves as a reflector, and two electronic paths which form two feedback loops of the oscillator.