光纤耦合声光Ti∶LiNbO3波导器件的研究

Research on the Coupling Between a Fiber and Ti∶LiNbO_3 Acousto-optic Device

波导型声光调制器作为高功率全光纤调Q激光器中的调制器件,光纤与器件对接耦合损耗大是影响其性能的主要因素。通过分析波导端面的Ti条半宽度与光波导模场分布的关系,计算出Ti∶LiNbO3锥形光波导与光纤耦合损耗最小时对应的最佳Ti条半宽度。分析得到Ti∶LiNbO3波导端面的Ti条半宽度对耦合损耗的影响,以及光波导的不同切型对最佳Ti条半宽度的影响。

For the guided acousto-optic modulator used in Q-switched full fiber laser with high power,the great coupling loss between the waveguide device and the single-mode fiber is the main factor which affects its performance.By analyzing the relationship between Ti strip half-width of the waveguide end and the mode field distribution,the optimum Ti strip half-width has been obtained when the coupling loss between the Ti∶LiNbO3 tapered waveguide and the fiber.The impact of Ti strip half-width on the coupling loss of the Ti∶LiNbO3 waveguide end is analyzed.The effect of different cut-type waveguide on the optimum Ti strip half-width has also been analyzed.