20 results about "Pump wave" patented technology

The invention relates to the technical field of non-linear regulation and control, in particular to a non-linear regulation and control method for a high-power narrow-linewidth multi-tone fiber laser system, which comprises the following steps: analyzing an influence mechanism of key parameters in the multi-tone fiber laser system on a non-linear effect; on the basis of the analyzed influence mechanism, establishing a nonlinear kinetic equation for describing the interaction of the pump wave, the stokes wave and the sound wave by combining a three-wave coupling theory, and forming a nonlinear propagation model; designing a Tab-DDPM generation network based on a nonlinear propagation model, and modeling a reverse mapping relation between a performance index and a design parameter by using a conditional diffusion mechanism to realize prediction of an optimal parameter; and inputting the optimal parameter into the nonlinear propagation model for verification, extracting an actually output performance index, and comparing the actually output performance index with a set target index to realize nonlinear performance evaluation and closed-loop optimization regulation and control. According to the method, the output capability and the signal fidelity of the high-power fiber laser system are effectively improved, and the method has good generalization capability.

A device including a photonic integrated circuit comprising one or more OPOs each comprising: an input configured to receive a pump wave comprising pulses or a frequency comb with a pump repetition rate, one or a plurality of nonlinear sections as part of a resonator or coupled to a resonator having a free spectral range, where at least one of the free spectral range or one of its harmonics is matched to the pump repetition rate or its harmonics, and one or a plurality of outputs configured to extract a portion of the waves generated by the OPO in response to the pump wave and / or the pump wave.

The invention relates to a gradient polarization BBO crystal quantum entanglement source device based on a wavefront-power cooperative regulation and control method. The gradient polarization BBO crystal quantum entanglement source device is mainly applied to the fields of quantum optics and nonlinear photonics. The device breaks through the limitation of a traditional entanglement source in the aspects of wavelength tuning range and long-term stability through the cooperative regulation and control of an integrated spatial light modulator (SLM) and an electro-optical modulator (EOM) and the design of a gradient polarization crystal, and can be widely applied to the fields of quantum precision measurement, super-resolution imaging, weak signal detection and the like. A traditional BBO crystal entangled source based on spontaneous parametric down-conversion (SPDC) has the problems of narrow wavelength tuning range, thermally induced phase mismatch, group velocity mismatch (GVM) and the like. According to the invention, through dynamic wavefront-power cooperative regulation and control and gradient polarization crystal design, the generation efficiency and quality of entangled photon pairs are significantly improved. The device comprises a pump light source, a light source adjusting assembly, a BBO crystal assembly and a test assembly. The light source adjusting assembly dynamically adjusts the phase distribution of a pump light field through the SLM loading hologram, and meanwhile, the EOM adjusts the laser power in real time to suppress phase mismatch caused by environmental disturbance. The BBO crystal adopts a gradient polarization design, the pumping wavelength is dynamically adapted, the group velocity mismatch is compensated, and the time entanglement fidelity is improved to 99.3%. And the test assembly is used for evaluating the quality of the entangled photon pair and ensuring high purity and high fidelity of the entangled photon pair.

The application provides a waveguide optical amplifier, which comprises a gain waveguide assembly and a pump waveguide. The gain waveguide assembly comprises a first gain waveguide and a second gain waveguide connected by a bend, at least part of the first gain waveguide is close to at least part of the second gain waveguide, so that the transmission direction of the signal in the first gain waveguide is opposite to the transmission direction of the signal in the second gain waveguide. The pump waveguide covers at least part of the gain waveguide assembly, and at least part of the pump waveguide covers the first gain waveguide and the second gain waveguide close to each other. The application uses the pump waveguide to cover the first gain waveguide and the second gain waveguide close to each other, which can reduce the length of the pump waveguide, the number of the space between the adjacent pump waveguides, and the space between the gain waveguides covered together, thereby reducing the size of the waveguide optical amplifier. Since the pump waveguide covers the gain waveguides with opposite transmission directions, a single pump light source can realize bidirectional pumping, thereby reducing the size of the optical amplifier.

Techniques disclosed herein relate to photon sources with high spectral purity and high brightness. In one embodiment, a photon-pair source includes a pump waveguide, a first resonator coupled to the pump waveguide to couple pump photons from the pump waveguide into the first resonator, a second resonator coupled to the first resonator, and an output waveguide coupled to the second resonator. The second resonator is configured to convert the pump photons into photon pairs. The second resonator and the first resonator are configured to cause a coupling-induced resonance splitting in the second resonator or the first resonator. The second resonator and the output waveguide are configured to couple the photon pairs from the second resonator into the output waveguide. In some embodiments, the photo-pair source includes one or more tuners for tuning at least one of the first resonator or the second resonator.

The embodiment of the invention provides a Raman amplifier gain adjustment method which comprises the following steps: adjusting DRA-P pumping configuration according to a first preset adjustment target, and determining a third preset adjustment target of a preset virtual intermediate point position according to amplifier performance parameters of a receiving end and a second preset adjustment target of a receiving end OSNR, and adjusting the transmitting terminal configuration of the transmitting terminal according to a third preset adjustment target, detecting the actual OSNR of the receiving terminal, and when the actual OSNR does not meet a second preset adjustment target, circularly and finely tuning the DRA-P pumping configuration and / or the transmitting terminal configuration until the actual OSNR meets the second preset adjustment target. According to the embodiment of the invention, segmented decoupling is carried out on the C + L system, and the gain of the amplifier is adjusted and optimized according to the sequence of the receiving end, the transmitting end and the whole, so that the problem that in the prior art, the stimulated Raman scattering effect exists between the pumping wavelengths of the Raman amplifier in the C + L system and between the service light of the C wave band and the service light of the L wave band can be solved; and the overall optical signal-to-noise ratio performance of the C + L system is influenced.

A structural defect detection method and system based on mixed-frequency ultrasonic delayed excitation. Four piezoelectric ceramic sensors are arranged in a rectangular pattern on a surface of a composite material layer. Mixed-frequency sound waves received by the two piezoelectric ceramic sensors undergo bandpass filtering, EMD decomposition and reconstruction, and frequency spectrum-energy spectrum analysis in sequence, then a modulation sideband parameter is extracted from a time-frequency spectrum, and a defect identification parameter is calculated on the basis of the modulation sideband parameter; if the defect identification parameter is greater than zero, a defect is present within a modulation aliasing region at excitation delay time; and if the defect identification parameter is less than zero, no defect is present within the modulation aliasing region at the excitation delay time. On the basis of a mixed-frequency excitation mode of delayed excitation of a low-frequency pump wave and a high-frequency detection wave, mixed-frequency incident waves do not need to be on the same axis, a sound wave aliasing region can be indirectly adjusted, and thus large-scale comprehensive scanning of the structure is achieved.

A spectrometer system is described. The system comprises a signal input port and a pump input port, respective signal and pump dispersion fibers, a nonlinear optical fiber section, and an output dispersion fiber. The dispersion fibers are configured to apply predetermined spectral dispersion on light input associated with signal and pump inputs. The nonlinear optical fiber section is configured to receive dispersed signal and pump waves and enable nonlinear interaction between the signal and pump waves. The output dispersion fiber is configured to receive light resulting from said nonlinear interaction and apply predetermined dispersion to the received light, thereby providing output light having mapping between time and spectral components of the input signal. Wherein at least one of the signal input port and pump input port comprises temporal speckle generating unit configured to affect optical pulses passing through to induce temporal speckles within said optical pulses.

Apparatus for use in four wave mixing is disclosed, comprising a nonlinear medium for receiving a plurality of light beams copropagating along an optical path through the nonlinear medium, the plurality of light beams including at least one signal wave having a signal frequency and one or two pump waves having respective pump frequencies, the light beams generating one or more unwanted idler waves in the nonlinear medium. The apparatus further comprises phase adjusting means arranged to selectively apply to wavelengths of light in the nonlinear medium, respective wavelength-dependent phase shifts to adjust the phase difference between the or each pump wave and the signal wave, such that unwanted idler waves are generated along the optical path of the nonlinear medium so as to destructively interfere, suppressing unwanted idler waves at an output of the nonlinear medium. A method of configuring the phase adjusting means is disclosed.

The invention relates to the technical field of radar detection, and discloses a method for measuring the hybrid height on an ionized layer, and the method comprises the steps: configuring ionized layer heating pump wave parameters and an incoherent scattering radar observation mode; obtaining a corresponding relation between the excited ionosphere parameter and the detection height of the radar detection direction and a corresponding relation between the background ionosphere parameter and the detection height of the radar detection direction; obtaining a stimulated ionosphere parameter height profile and a background ionosphere parameter height profile; and determining the hybrid height on the ionosphere according to the excited ionosphere parameter height profile and the background ionosphere parameter height profile. According to the method, the hybrid height on the ionized layer can be detected. The invention further discloses a device for measuring the hybrid height on the ionized layer, observation equipment and a computer readable storage medium.

The application discloses a pump wave-locked device of a fiber laser and belongs to the field of fiber lasers. The pump wave-locked device comprises a wave-locked control system and a pump drift detection module, wherein the pump drift detection module comprises at least a pair of cladding pumping light detection modules; the wave-locked control system controls the refrigeration effect of a pump cooling platform on a pump system according to the signal strength of a first photosensitive detector and a second photosensitive detector in the pair of cladding pumping light detection modules, so as to control the output wavelength of the pump system in real time.

Disclosed is a method for generating a broadband microcomb, that includes generating a comb signal by a pump laser, at a pump wavelength corresponding to a resonance of a micro-resonator, wherein the micro-resonator operates with two modes with a mode separation of a predefined range, heating 5 the micro-resonator using a heater, and deterministically generating broadband microcombs including octave spanning solitons by the micro-resonator by bi- directional tuning of the heater voltage, wherein the bi-directional tuning of the heater voltage tunes the resonance wavelengths of the two modes, and alters the wavelength separation of two modes. 10

The application provides an analysis method for the influence of cavitation and temperature on the sealing performance of a nuclear main pump. The method comprises selection of a cavitation model, judgment of fluid flow state, setting of boundary conditions and analysis of the influence on sealing performance. Three different calculation models are selected, and sealing performance parameters under changes in film thickness and rotational speed are calculated. Comparison of the calculation results of the three models shows that: (1) when the film thickness is small, the cavitation effect has a greater influence on the opening force, and the opening force is obviously promoted, and the viscosity-temperature effect reduces the opening force. When the film thickness is large, the cavitation effect is weakened or even disappears, and the influence of the viscosity-temperature effect on the opening force and leakage exceeds the cavitation effect. (2) When the rotational speed is low, the cavitation area is small, and the change in the opening force is not obvious, but the viscosity-temperature effect still has a very obvious promoting effect on the leakage. When the rotational speed is high, the influence of the cavitation effect on the opening force is greater than that of the viscosity-temperature effect, and the cavitation effect promotes the increase of the opening force, and the influence of the viscosity-temperature effect on the opening force is small.

In some embodiments, a device for generating mid-infrared radiation is provided. The device may include a thin film quadratic nonlinear waveguide formed on a mid-infrared transparent cladding by a thin film material of a predetermined film thickness, the waveguide having a predetermined etch depth and a predetermined top width. At least one of the predetermined film thickness, the predetermined etch depth, and the predetermined top width may be tuned for the device to generate a coherent idler wave as a mid-infrared radiation from a fixed pump wave and a tunable signal wave.

The present invention provides a dual-frequency fiber grating laser and a Brillouin optical time-domain reflectometer, comprising a dual-frequency laser cavity, a wavelength division multiplexer connected to the dual-frequency laser, and a polarization beam splitter and a pump source respectively connected to the wavelength division multiplexer, wherein the wavelength division multiplexer couples the pump laser output by the pump source to the dual-frequency laser cavity, and couples the orthogonal dual-polarization laser output by the dual-frequency laser cavity to the polarization beam splitter, and the polarization beam splitter separates the orthogonal dual-polarization laser and outputs two lasers with orthogonal polarization states. The beneficial effect of the present invention is that the pump wave light source and the eigenwave light source in the system of the Brillouin optical time-domain reflectometer are realized in one fiber grating laser, without the need for two independent lasers and a relatively expensive high-stability large-bandwidth optical phase-locked loop device, reducing the complexity of the light source in the Brillouin optical time-domain reflectometer system, improving the stability and reliability of the system, and reducing the cost of the light source in the Brillouin optical time-domain reflectometer system.

A device for compensating temporal walk-off of a nonlinear quantum optical element according to the technical idea of the present disclosure includes an optical waveguide for propagating input light along a specific path. The optical waveguide includes: a nonlinear optical source section that transmits input light including a plurality of modes; a polarization separation section that separates the plurality of modes; a taper section that converts the separated modes; and a curve section that changes the direction of propagation of the input light. The plurality of modes include a pump wave, a signal wave, and an idler wave. The group velocities of the pump wave and the idler wave are identical, and the group velocity of the signal wave differs from that of the pump wave or the idler wave.

The present invention relates to a non-linear resonant-structure optical transistor operating at a single frequency, comprising a non-linear medium that amplifies a signal wave through inverse second-harmonic generation or inverse third-harmonic generation interaction with a second-harmonic wave or a third-harmonic wave, and being in an off state in which no output wave is present at a collector when only a pump wave is input into an emitter of the optical transistor, and being in an on state in which a signal wave is amplified and output to the collector when the pump wave is input into the emitter and the signal wave is input into a base, wherein an input wave at the base controls an input wave at the emitter so as to control the on-off state and intensity of the output wave at the collector, thereby simultaneously implementing amplification and switching of the optical signal. In this manner, the present invention provides an optical transistor operating with a single-frequency light wave, and an optical system comprising same.

The invention provides an indium tin oxide thin film for enhancing terahertz emission and a preparation method of the indium tin oxide thin film, and belongs to the technical field of nonlinear optics and terahertz. The method comprises the following steps: depositing an indium tin oxide (ITO) film on a substrate by adopting a magnetron sputtering process; and the thin film is placed in a vacuum environment to be subjected to rapid thermal annealing treatment. The core of the method is that the annealing time and the annealing temperature are accurately controlled, and the thin film is regulated and controlled to be in a middle semitransparent state which is converted from opaque to full-transparent. Experiments show that the ITO thin film in the semitransparent state maintains high nonlinear absorptivity in a near-infrared pumping wave band while ensuring certain crystallization quality, so that the emission intensity of terahertz generated by the ITO thin film is obviously higher than that of a full-transparent thin film which is annealed for a long time. According to the terahertz emission source, the problem that the nonlinear optical conversion efficiency is reduced due to excessive pursuit of film transparency in the prior art is solved, and a terahertz emission source preparation scheme which is simple in process, compatible with a CMOS (complementary metal oxide semiconductor) process and efficient is provided.

The application aims to provide a resonant cavity and high-power terahertz radiation source combining optimization of cascade difference frequency, comprising a first pump source and a second pump source, a non-periodic polarization APPLN crystal, a beam combining mirror, a phase delay system, a fifth mirror, a sixth mirror, a seventh mirror, an eighth mirror and a beamsplitter constituting a resonant cavity; the intensity of the terahertz wave can be enhanced, and the energy conversion efficiency of the terahertz wave can be improved. Through setting of the reflectivity of the cavity mirror, the Stokes light wave can be oscillated in the cavity, and the energy can be repeatedly transferred from the pump wave to the high-order Stokes wave.

An apparatus comprising a photonic integrated circuit, the photonic integrated circuit comprising one or more OPO, each OPO comprising: an input configured to receive a pump wave comprising a pulse or a frequency comb having a pump repetition rate; one or more non-linear portions as part of the resonator or coupled to a resonator having a free spectral range wherein at least one of the free spectral range or one of the harmonics thereof matches the pump repetition rate or the harmonics thereof; and one or more outputs configured to extract a wave generated by the OPO in response to the pump wave and / or a portion of the pump wave.