9 results about "Laser noise" patented technology

The invention discloses a tumor detection device and method based on a diamond quantum sensor, and belongs to the technical field of biomedical detection. The device comprises an optical fiber laser, an optical fiber beam splitter, an optical fiber attenuator, an optical fiber circulator, an optical filter, two photoelectric detectors, a differential amplifier, an electronic filter, a computer, a signal generator, two microwave antennas and an optical fiber probe. The optical fiber probe comprises an optical fiber packaged in a plastic shell, a diamond quantum sensor which is fixed at the tail end of the optical fiber and comprises an NV color center, and a first microwave antenna integrated beside the optical fiber. The laser excites the diamond to generate fluorescence, meanwhile, the signal generator drives the two microwave antennas to apply a microwave field, and the dielectric property of the sample to be detected modulates the fluorescence intensity of the diamond by influencing the microwave field. Laser noise is eliminated through a differential amplification and filtering technology, and fluorescence signal change is analyzed by a computer, so that dielectric constant distribution of a sample is reconstructed, and non-invasive and high-sensitivity detection of tumors is realized.

A system for illuminating a target in the presence of atmospheric turbulence includes a coherent beam combining (CBC) subsystem, an atmospheric wave-front sensor (AWS) subsystem, a multi-channel photo-detector (MCPD) subsystem, an auxiliary light source, and a receiving optical aperture. The CBC subsystem forms a multiplicity of CBC sub-beams and an reference beam, all of which fall in a wavelength band that is different from that of the auxiliary light source. The auxiliary light source may be a laser or a portion of the solar spectrum of the Sun. An AWS controller provides closed-loop compensation of atmospheric turbulence for low power auxiliary reflection and reference beams. A MCPD controller provides closed-loop compensation of high-frequency laser noise and transfers the wavefront correction from the reference to the high power CBC laser. The frequency of the MCPD controller is at least an order of magnitude greater than the bandwidth of the AWS controller.

The application discloses a chipped wavelength standard device and a preparation method thereof, and belongs to the field of wavelength standards. The device comprises a frequency discrimination module, a pumping module, a locking module and a substrate. The frequency discrimination module comprises a MEMS atomic gas chamber, a micro-ring resonant cavity and a photodetector; the pumping module mainly comprises a laser and a control circuit thereof; the locking module comprises a phase-locked amplifier, a reference signal source and a PID circuit. The substrate comprises a copper or ceramic heat sink and a TEC temperature controller. The application combines the micro-ring resonant cavity and the MEMS atomic gas chamber, directly pumps the micro-ring resonant cavity integrated optical path by the laser, locks the laser wavelength on the micro-ring resonant cavity resonance peak based on the micro-cavity self-injection locking method, reduces the laser noise and realizes the laser linewidth compression. The micro-cavity evanescent field excites the atomic transition in the atomic gas chamber, and the frequency is discriminated by detecting the fluorescence. The laser frequency is locked by controlling the laser current and the micro-cavity temperature through the frequency discrimination signal, and the chip-level wavelength metrology and value traceability are realized.

The application discloses a tumor detection device and method based on a diamond quantum sensor, and belongs to the technical field of biomedical detection. The device comprises a fiber laser, a fiber beam splitter, a fiber attenuator, a fiber ring, a filter, two photodetectors, a differential amplifier, an electronic filter, a computer, a signal generator, two microwave antennas and a fiber probe. The fiber probe comprises a fiber packaged in a plastic shell, a diamond quantum sensor containing NV color centers fixed at the end of the fiber, and a first microwave antenna integrated beside the fiber. The laser excites the diamond to generate fluorescence, and the signal generator drives the two microwave antennas to apply a microwave field. The dielectric properties of the sample to be measured will modulate the fluorescence intensity of the diamond by affecting the microwave field. The laser noise is eliminated through differential amplification and filtering technology, and the computer analyzes the fluorescence signal change to reconstruct the dielectric constant distribution of the sample, realizing non-invasive and high-sensitivity detection of tumors.

The application discloses a kind of low-frequency noise detection methods of optically pumped laser, it is successively including multi-link synchronous acquisition and working condition insertion preparation, subzone association determination and three reference contribution solution, eigen noise reconstruction and robustness constraint, unified spectrum output and parameter backwrite closed loop, it is related to laser noise detection technical field, by simultaneously obtaining main test signal, pump reference signal, environmental reference signal and background reference signal, and according to frequency band determination reference participation condition, respectively pump contribution, environmental contribution and background contribution are calculated, eigen low-frequency intensity noise spectrum and eigen frequency noise spectrum are reconstructed, then unified result is output in combination with residual check, freeze back and splicing constraint.The method can improve low-frequency noise source distinguishing ability, result continuity and working condition adaptability.

This invention relates to a method and system for measuring the electric field of Rydberg atoms based on frequency-modulated spectroscopy. In the measurement preparation stage, a sinusoidal signal is used to modulate a coupled laser or a probe laser to induce a change in the intensity of transmitted light under induced transparency (EIT) conditions. A calibration microwave electric field is injected into the atomic gas cell, triggering an AT splitting effect in the transmitted light. The change in the intensity of the transmitted light passing through the atomic gas cell is detected, and the corresponding electrical signal is output. The signal component related to the calibration microwave electric field intensity is extracted from the electrical signal. The proportionality coefficient between the signal component and the calibration microwave electric field intensity is calculated. In the actual measurement stage, the microwave electric field to be measured is injected into the atomic gas cell, and the amplitude of the microwave electric field to be measured is calculated based on the proportionality coefficient and the signal component related to the intensity of the microwave electric field to be measured. This invention solves the problems of low sensitivity and low sampling rate in traditional EIT-AT readouts, improves measurement sensitivity, and effectively suppresses laser noise.

The present application relates to the technical field of laser testing, and particularly relates to a fiber connection method and device for a laser noise measurement system. In the method, the laser noise measurement system comprises a laser chip, a lens and a test device; a light-emitting waveguide in the laser chip emits laser light, and the laser light passes through the lens and is connected to the test device through a measurement fiber; the connection method is a method of connecting the lens to the test device through the measurement fiber; the measurement fiber is connected to the test device in sequence from the lens, through an APC joint and a PC joint, wherein the inclined end of the APC joint is adjacent to the PC joint. The method can weaken reflection, thereby significantly improving the overall performance of the system and obtaining more accurate noise measurement results.

The invention discloses a laser point cloud inertial odometer method based on 4D millimeter wave radar compensation denoising, which realizes robust environment perception of an operation robot in a degraded environment through multi-sensor fusion, and completes corresponding accurate positioning in combination with an optimized laser inertial odometer. The coupling denoising of the laser radar and the 4D millimeter wave radar ensures that the structured environment point cloud is reserved while the laser noise is filtered out, and the stability of the pose estimation of the speedometer under high dynamic and sampling jitter is ensured by the intensity-weighted optimized GICP matching and the ESKF with the second-order evolved subitem added. Compared with the prior art, the method has higher positioning precision in a degradation data set, and has deployability in an actual operation scene.

Aspects of the present disclosure relate to a photon pair source based on an external cavity laser comprising a gain element and a planar lightwave circuit containing surface waveguide based mirrors and a ring resonator enabling four wave mixing, where the surface waveguide mirrors and the ring resonator reside within the gain cavity of the laser itself. Thus, a photon pair source according to the present disclosure can have: (1) a larger free spectral range of the entire laser cavity to enable generation of a single wavelength to enable single mode operation without additional stabilization; and (2) low laser noise, thereby enabling detection and use of the generated photon pairs.