7 results about "Absolute frequency" patented technology

The invention discloses an ultra-narrow band optical filter absolute frequency reference in-situ calibration device which comprises a hollow cathode lamp, the output end of the hollow cathode lamp is connected with one input end of a one-to-two optical fiber through a light beam coupling device, and the output end of a variable diaphragm is connected with the other input end of the one-to-two optical fiber through an optical fiber; light beams output by the one-to-two optical fiber are split, the first split beam is input to the second photoelectric detector, and the second split beam transmits the ultra-narrow band light filter and is detected by the first photoelectric detector; the invention further discloses an in-situ calibration method for the absolute frequency reference of the ultra-narrow band light filter, the center transmission wavelength of the etalon is calibrated through the absolute wavelength of the hollow cathode lamp, the etalon is accurately controlled at constant temperature and constant voltage, the center transmission wavelength of the etalon is calibrated, and the calibration of the center wavelength of the etalon is integrated with an external optical signal detection function; and through the automatic calibration process, the calibration efficiency is greatly improved, manual operation errors are avoided, and a high-precision calibration task can be completed in a short time.

The application provides a tunable laser multi-point absolute frequency locking device and method, and belongs to the technical field of lasers. The device comprises: a tunable laser unit provided with a frequency tuning port for receiving an external control signal; an interference measurement unit comprising a first beam splitter and an interference system; a frequency reference unit comprising a phase modulator, a gas absorption chamber and a photodetector arranged in sequence on the same optical axis; a locking and scanning control unit for identifying absorption peak characteristics according to an electrical signal, dynamically outputting a compensation signal to the frequency tuning port to realize frequency locking and control the interference system to perform interference measurement, or outputting a scanning signal to the frequency tuning port to control the tunable laser unit to perform frequency scanning. The application can obtain an interference signal with high contrast and high signal-to-noise ratio during measurement, is conducive to continuously and quickly locking multiple absolute frequency points on a wide spectrum, and greatly improves the efficiency, accuracy and application range of sweep frequency interference measurement.

The invention discloses an integrated Michelson optical frequency scale and displacement measurement system based on pyramid array feedback. The device comprises a Michelson optical frequency standard system (optical frequency standard system for short) and a Michelson displacement measurement system (displacement measurement system for short), and the optical frequency standard system and the displacement measurement system share the same reference arm. According to the invention, quantum spectral lines are used as absolute frequency reference to generate stable and accurate optical frequency standard signals, and the optical frequency standard signals are used as the reference of displacement measurement to realize organic unification of time frequency and displacement measurement; an optical frequency signal output by the optical frequency standard system has a relatively strong anti-interference capability to an external environment, and the resolution of the displacement measurement system can be improved; in order to solve the interference problem of the pitching inclination angle of a measuring arm cavity mirror in displacement measurement and tiny movement in the non-displacement measurement direction, the invention provides a reflecting mirror adopting an integrated pyramid array as a composite cavity, so that the stability and the robustness of a displacement measurement system can be improved, and the measurement range and the measurement resolution are optimized.

The invention relates to the technical field of optical measurement, in particular to a device and method for improving the stability of a target laser beam, and the device comprises a target laser, a first modulator, a first PDH light path, a second modulator, a second PDH light path, a target FP cavity, a first monitor, a second monitor, a controller, and a third modulator. It can be known that a frequency stabilization mode that a traditional ultra-stable laser needs an external absolute frequency reference does not need to be adopted, a stable frequency difference is obtained through the structure of the ultra-stable laser, long-term drifting of feedback frequency is achieved through stable frequency difference characteristics and stable frequency difference change conditions, the structural complexity of the laser is reduced, and cost is reduced.

The invention relates to the technical field of optical measurement, in particular to a method and system for detecting the zero expansion temperature of an ultra-stable cavity. The method comprises the following steps: acquiring a first laser beam and a second laser beam; inputting the first laser beam into the target FP cavity from one end of the target FP cavity and inputting the second laser beam into the target FP cavity from the other end of the target FP cavity; the target zero expansion temperature is obtained according to the temperature related information of the target FP cavity, the frequency change degree of the second modulator is measured in the step of obtaining the target zero expansion temperature according to the temperature related information of the target FP cavity, and the target zero expansion temperature is obtained based on the frequency change degree of the second modulator; it can be known that compared with the prior art that only one absolute frequency reference is needed and only the frequency change degree of the second modulator is measured, the requirement for the absolute frequency stability of the laser is lowered, and meanwhile the zero-expansion temperature can be rapidly and simply obtained only by controlling the temperature and scanning the laser.

This invention discloses an ultra-high stability laser system based on dual-path independent composite frequency stabilization and sum-frequency modulation, belonging to the field of precision laser spectroscopy and frequency control technology. The system includes two seed lasers (1560 nm and 1064 nm), a dual-wavelength common-cavity ultra-stable module, two acousto-optic frequency shift and dual-reference absolute frequency stabilization modules, and a nonlinear sum-frequency modulation (SFG) module. Full-time-scale frequency noise suppression is achieved through a three-stage cascaded closed loop consisting of a MHz fast loop, a kHz slow loop, and a Hz extremely slow loop. An acousto-optic modulator is placed in the sampling optical path fed into the ultra-stable cavity, and physical decoupling of the fast and slow loops is achieved through radio frequency bridging. The extremely low-frequency error signal detected by NICE-OHMS is fed back to the PPMgOLN crystal temperature or AOM driving frequency to compensate for the thermally induced drift of the nonlinear crystal. The system ultimately outputs a 633 nm laser power of not less than 50 mW, with a short-term frequency instability better than 5 × 10⁻⁶ mW. ‑15 @1 s.

The application provides a laser frequency stabilization system and method based on optical multi-frequency point cooperative locking, and relates to the technical fields of laser frequency stabilization and precision measurement. The system comprises a tunable laser unit, a multi-sideband modulation unit, an error signal generation unit and a feedback control unit. The multi-sideband modulation unit uses a controllable first radio frequency signal to modulate the phase of the laser to generate multiple sidebands; the error signal generation unit obtains a time domain electrical signal through frequency discrimination modulation. The feedback control unit calculates a total frequency discrimination error signal after the coherent superposition of multiple error signals, generates a feedback control signal according to the total frequency discrimination error signal and outputs the feedback control signal to the tunable laser unit to realize the locking of the center frequency of the laser. The application significantly improves the signal-to-noise ratio of the frequency discrimination signal through the cooperative action of multiple frequency points, can output an electrical absolute frequency signal anchored to the optical frequency reference interval while outputting high-stability frequency laser, and realizes the direct transfer of the optical domain frequency standard to the electrical domain.