用于光纤耦合的无衍射光束研究

Research of non-diffraction beams in fiber coupling

在光纤耦合理论及圆锥透镜产生无衍射光束理论的基础上提出了无衍射光束在光纤耦合中的方法。相对于其他方法,无衍射光束更容易耦合进入光纤,特别是单模光纤,并且在其最大准直距离内耦合效率几乎不变,可以减小装调难度。对此方法进行理论分析,并进行实验,加工了光纤耦合使用的圆锥透镜,其锥角为10°,通光半径为5mm。波长为0.6328μm的激光经过准直扩束后入射到圆锥透镜上,产生光斑半径为6.7μm的无衍射光束,在轴向58mm的范围内均可耦合进入光纤,并且耦合效率几乎不变,减小了光纤耦合时的光轴方向对准误差,降低了装调难度,验证了理论分析。

On the basis of fiber coupling theory and conical lenses producing non-diffraction beams,the method of non-diffraction beam coupling in fiber was proposed.Compared with other methods,non-diffraction beam were easier to be coupled in fiber,especially for single mode fiber.Moreover,the coupling efficiency was almost constant in its maximal collimating distance,which could reduce assembly difficulty.Based on the theoretical analysis,the experiments were carried out and the conical lenses used in fiber coupling was processed,cone angle was 10° and the radius of the optical was 5 mm.The laser beam with wavelength of 0.632 8 μm was collimated and expanded,then incident to the conical lenses and producing non-diffraction beams with the radius of 6.7 μm,which could be coupled into fiber in axial range of 58 mm while the coupling efficiency was almost constant.It verifies the theoretical analysis that the optical axis alignment error and assembly and adjustment difficulty can be reduced.