5results about How to "High spectral purity" patented technology

The present application relates to the field of microwave photonics, and more particularly to a high linearity microwave photonics down-conversion receiving system based on an optoelectronic oscillator. The system comprises a laser, a first phase modulator, a first optical amplifier, a phase-shifted Bragg grating, a first photodetector, a second phase modulator, an optical filter, a second optical amplifier, and a second photodetector. The frequency of the local oscillator signal generated by the first photodetector can be tuned by changing the frequency of the laser, thereby effectively realizing the tuning of the down-converted signal output by the second photodetector. By adjusting the gain value of the first optical amplifier, the amplitude of the local oscillator spectral harmonic in the output optical signal of the first phase modulator is a specific value, thereby realizing the suppression of the third-order intermodulation distortion in the output signal, and further improving the spurious-free dynamic range of the entire down-conversion receiving system. The system has reconfigurability and high linearity, and can play a technical value in the field of radar and communication applications.

The application discloses a control method, a storage medium and a terminal based on a Brillouin laser Kerr optical frequency comb of an orthogonal polarization mode, and is based on a control module; the method comprises the following steps: an initial control step; a secondary pumping control step: a second control command is sent to an adjustable wavelength laser, and based on monitoring data of a fourth optical detector used for monitoring a state of a stimulated Brillouin laser of a cross-polarization TM mode after polarization beam splitting of light, a pumping laser wavelength blue shift speed and an optical power are further adjusted until a Kerr optical frequency comb state appears. The application generates a stimulated Brillouin laser of an orthogonal polarization mode to form a Kerr optical frequency comb through secondary pumping, filters specific comb tooth interval light waves of the optical frequency comb, performs beat frequency on the filtered light wave signals, and obtains a required microwave signal output.

This invention proposes a narrow-emission ultraviolet gallium sulfide quantum dot material and its synthesis method, belonging to the field of semiconductor quantum dot material technology. The method employs a one-pot synthesis strategy and introduces a specific passivating agent into the reaction system. By precisely controlling the reaction conditions and the amount of passivating agent, high-purity ultraviolet-emitting gallium sulfide quantum dots with an emission peak at 392 nm and a half-maximum width at half-maximum (HWHM) of 34 nm were successfully prepared. This synthesis method significantly reduces the HWHM of gallium sulfide quantum dots and improves their spectral purity. This invention provides an effective method for preparing ultraviolet environmentally friendly quantum dots with high color purity, demonstrating great application potential in cutting-edge fields such as lighting and full-color displays.

The utility model discloses a frequency hopping frequency source module based on DDS relates to microwave radio communication technical field, including crystal oscillator, power divider and frequency mixer, and power divider and frequency mixer are connected in parallel through first branch and second branch, and first branch includes FPGA chip, PLL chip, DDS chip and first filter who connects in order series connection, and FPGA chip and power divider first output electric connection, and first filter and frequency mixer first input electric connection, and the second output of FPGA chip and the frequency control input of DDS chip electric connection. The utility model discloses the hardware construction under relevant layout, still makes it have the advantage that the output frequency coverage is wide under the original already having the advantage that the frequency switching speed is fast, and the frequency resolution is high.

The application discloses an injection locking frequency multiplication device, a phase-locked loop and a method, which integrates a digitalized capacitance array in a resonant cavity of an injection locking frequency multiplier, and combines a frequency multiplication amplitude detection module and a feedback control module to form a closed-loop adaptive tuning structure, so that the equivalent capacitance and the resonant frequency of the resonant cavity can be adjusted in real time according to the amplitude change of a frequency multiplication signal, thereby effectively compensating for frequency drift caused by process deviation, power voltage fluctuation and temperature change, significantly widening the working frequency band of the injection locking frequency multiplier, improving locking accuracy and working stability, avoiding the phase noise deterioration and power consumption increase phenomenon caused by reducing the Q value of the resonant cavity or increasing the injection power to widen the locking range in the traditional scheme, enabling the frequency multiplier to realize wide frequency working and automatic calibration while maintaining good spectral purity and low phase noise, and being more suitable for a phase-locked loop and a radio frequency front-end circuit in a multi-frequency band and wideband communication system.