模场直径可调的光纤微准直器OA北大核心

A fiber micro collimator with adjustable mode field diameter is proposed to address the problem of single output mode field diameter in traditional fiber collimators.The single mode fiber is combined with different 2-segment multimode fibers to form a"sandwich"structure.By adjusting the length of the middle section of the optical fiber,the mode field diameter can be ad-justed arbitrarily,and a simulation experimental model has been constructed to prepare multiple fiber micro collimator samples with different sizes.The experimental results show that the structure can achieve adjustability of the output mode field diameter in the range of 20～40 μm in the 1 550 nm wavelength band.The preparation method of this fiber collimator is simple,compact in structure,and can flexibly adjust the mode field diameter of the light field according to the needs to adapt to different application scenarios.