Development Of A Transportable Narrow-width Frequency-stabilized Laser System

Ultra-narrow linewidth and frequency-stabilized laser has important applications in various fields,including optical atomic clock,high precision laser spectroscopy,and basic physical constant measurement and so on.With the further development of research applications,the working environment of the frequency-stabilized laser system has also gradually expanded from the laboratory to the outdoor.For space gravitational wave detection,it is more important to send a narrow linewidth laser as a probe light source to space.Therefore,it is increasingly urgent to achieve a low vibration sensitivity and achieve a transportable frequency stabilization system.For the application requirements of a narrow-width,stable-frequency laser that can be transported,we have designed an optical reference cavity wirth10 cm square and four-point diagonal support by numerical simulation.The optical reference cavity has transport characteristics.The numerical simulation calculations are used to calculate the deformation of the optical reference cavity subjected to force and acceleration respectively,and the effects of different light positions on the vibration sensitivity of the mirror are analyzed.The vibration sensitivity of the optical reference cavity is obtained.In addition,we have studied the response characteristics of the temperature of the optical cavity to changes in the external environment temperature and reasonably designed a thermal shield of optical reference cavity by simplifying heat transfer from outer thermal shield to an optical cavity to a resistor–capacitor?RC?integrating circuit.In this experiment,we processed a transportable cubic optical reference cavity and tested the optical properties such as fineness and contrast.An optical reference cavity system was built.Through the vibration sensitivity test,the vibration sensitivity in all directions is about 2.1×10^-10/g.Using PDH technology,the frequency of the two lasers are locked at the two optical reference cavities on the same cube.Two sets of cubic reference cavity frequency stabilization systems are used to beat with each other,and the frequency instability is 7.4×10^-16,and the single set is 5.2×10^-16?integration time of 1 s?.So the frequency stabilization systems approach their thermal noise limit.Using femtosecond optical combs and optical fiber precision transmission systems,578 nm frequency stabilized lasers with frequency stability of 3×10^-1616 in different laboratories beats with 1064 nm lasers which is locked in cubic reference cavity.The frequency instability of this experimental system is 1.6×10^-15?1 s average time?.The laser system can provide high-performance reference light sources and detection lasers for the studies of high-precision optical clock frequency comparisons and gravitational wave detection.