Design And Experiment On The Three-pole Bridges Resonator For High-power Transverse Flow CO₂Laser

As the core of the laser, the stability of the resonator determined the quality of output.In this dissertation, in order to solve the problem of the original high-power transverse flowCO₂laser that output power was instability, a new kind of three-pole bridges resonator wasput forward for high stability. Theoretical and experimental researches were done. The maincontents were classified as follows.The design of the resonator supported by three-pole bridges was composed of threepoles and two end-plates, which separated the resonator from the vacuum box. This structurecould effectively avoid distortions which was induced by the deformation of the vacuum box.Water of constant temperature flowed through the poles to keep their stability.Stability and security of three-pole bridges resonator was tested by detecting the offsetof indication light from the reflector. The deformation of the three-pole bridges wasindependent of that of the vacuum box so the resonator was stability when the vacuum boxdistorted due to the atmospheric pressure. The resonator also could be stability whenwaterways were connected in parallel, water flow rate of each waterway was0.67m³/h andfluctuations of inlet water temperature was less than±0.5℃in the surrounding temperatureof10℃²5℃. Red-light experiment on the three-pole bridges showed the offset ofindication light from the reflector was1.5mm when the variation of the inlet water reaches to15℃.The characteristics of the triple-folded resonator and general resonator wereinvestigated. For the triple-folded resonator and general resonator, the variation of the outputpower was less±3%and±1.9%of the maximum of the output power, respectively. And thelight field mode was stability. The influence of cooling water which flowing through theoutput mirror base and reflector base to output power was tested. The experiment result andanalysis showed that the output power instability would be less than1%when the variationof the temperature of cooling water was less than±0.5℃, which showed that the structurehad good application prospects.