Study On The Physical Characteristics Of Integrated Y-shaped Cavity Dual-frequency Laser With Single Pair Of Orthogonal Polarized Modes

Y-shaped cavity orthogonal polarized laser is the important device for the development of laser accelerometer,which has great application potential and value in the field of optical precision measurement.The improvement of output frequency difference stability has been the key to the research.This paper firstly summarizes the current research situation and development trend of dual-frequency lasers,and focuses on the structural characteristics,principles,applications and development trends of Y-shaped cavity orthogonal polarized lasers.Summarizing the work of predecessors and pointing out the problems in their research content,it points out the necessity of designing a new Y-shaped cavity orthogonal polarized laser with single pair of orthogonal polarized modes.Secondly,a new integrated Y-shaped cavity laser with a new cavity improved structure is designed,and its basic structure and principle are introduced.The transient and steady-state temperature fields of the laser were simulated by ANSYS software and the actual temperature field of the laser was captured by infrared camera.The results show that the error between the actual temperature and the simulation result is less than1%,which indicates that the ANSYS simulation model is accurate and reliable.The simulation results show that the laser takes about one hour from start up to steady state operation.The highest temperature point of the laser cavity in steady state is located in the gain region inside the cavity.The maximum temperature is 52.778?,and the average temperature difference between the S sub-cavity and the P sub-cavity is0.089?.At the same time,the temperature difference between the two sub-cavities of the laser is the result of the internal heat source of the cavity,and it is also the main reason that affects the stability of the output frequency difference of the laser.The three basic output characteristics of the new integrated Y-shaped cavity laser were tested.The results show that the output power of the laser increases with the increase of the discharge current.The maximum output power is 0.53m W in the working range of 1.22?3.4m A..The output laser of the laser basically operates in the mode state of a fundamental transverse mode,a double longitudinal mode(single pair of orthogonal polarized modes),which are orthogonal linearly polarized light.The cavity tuning experiment was carried out on the new integrated Y-shaped cavity laser by constructing the cavity tuning experiment system,and the intensity tuning curve,the corresponding beat frequency curve and the frequency difference tuning curve under different splitting frequency differences were obtained.Combined with theoretical analysis and experimental data,the frequency of splitting is the main factor affecting the competition of modes.The frequency difference of splitting affects the linear gain and self-saturation effect,loss and mutual saturation effect of each longitudinal mode.The three combine to influence the change of light intensity through the self-consistent equation of light intensity.When the splitting frequency difference is in the range of 129-1302 MHz,the laser is in an operating state in which single pair of orthogonal polarized modes(adjacent S,P single longitudinal mode)oscillates.Finally,the temperature-controlled thermal frequency stabilization experiment system was built to carry out the experiment of temperature-controlled thermal frequency stabilization.The experimental results show that the frequency stability of the laser working in the temperature control box is better than that without temperature control.When the temperature is higher than the highest temperature in the steady state of the laser,the stability of the output frequency difference is increased from 10~6to 10~5.The effect of the second-level temperature control on improving the beat frequency stability is obviously better than the first-level temperature control.Under the temperature control of temperature control of 61?,the output frequency difference stability of the laser is increased to 10~4,achieving the expected results.