Methods and devices of 425NM wavelength reference construction based on fluorescence-induced effect

A device of a 425 nm wavelength reference construction based on fluorescence-induced effect, comprises:

• a continuously tunable laser, an atomic furnace, a chromium atomic beam, an optical frequency comb, a frequency doubling optical path, a bias-preserving fiber beam splitter, a bias-preserving fiber beam combiner, a beat-frequency detection optical path, an optoelectronic receiver, and a frequency counter;
• wherein
• an output end of the continuously tunable laser is provided with a first half-wave plate, a first coupler, and the bias-preserving fiber beam splitter arranged in order;
• the output end of the continuously tunable laser is connected to an input end of the bias-preserving fiber beam splitter;
• an output end of the optical frequency comb is connected to the frequency doubling optical path;
• the frequency doubling optical path and a first output end of the bias-preserving fiber beam splitter are connected to an input end of the bias-preserving fiber beam combiner, respectively;
• the chromium atomic beam is emitted through the atomic furnace and interacts with a second output end of the bias-preserving fiber beam splitter;
• an output end of the bias-preserving fiber beam combiner is connected to an input end of the beat-frequency detection optical path;
• an output end of the beat-frequency detection optical path is connected to an input end of the frequency counter through the optoelectronic receiver;
• the beat-frequency detection optical path includes a second collimator, a second reflector, a third half-wave plate, a polarized beam splitter cube, a third reflector, and a diffraction grating;
• wherein the second reflector and the third reflector are placed in parallel;
• the output end of the bias-preserving fiber beam combiner is connected to an input end of the optoelectronic receiver after passing the second collimator, the second reflector, the third half-wave plate, the polarized beam splitter cube, the third reflector, and the diffraction grating in sequence;
• the 425 nm wavelength reference construction is realized based on the device by a method for constructing a 425 nm wavelength reference based on the sensible fluorescence effect, the method comprising:
• S1, constructing a frequency measurement system of a laser and the optical frequency comb based on a technique of heterodyne beat frequency detection;
• S2, setting a temperature of the atomic furnace to a state of leakage generation of the chromium atomic beam, initially adjusting a laser wavelength near a theoretical value of a transition (7S3-7P4) frequency of the chromium atoms, and a set of opposite-direction propagating lasers interacting with the chromium atomic beam and symmetrically sensitizing two fluorescent spots on both sides of a central axis of the chromium atomic beam;
• and
• S3, finely adjusting the laser wavelength so that the two fluorescent spots symmetrically sensitized on both sides of the central axis of the chromium atomic beam, at which time a laser frequency is equal to the transition (7S3-7P4) frequency of the chromium atoms, and performing a measurement of the transition (7S3-7P4) frequency of the chromium atoms.