分析了声光偏转器(acousto-optical deflector,AOD)对飞秒脉冲激光光斑的空间畸变效应.研究表明:由于飞秒激光在锁模情况下具有较宽的光谱带宽,经过AOD后的一级衍射光斑带有严重的角色散,导致光斑形状发生畸变,影响成像的空间分辨率.实验测试了一维AOD器件在不同声波频率下的光斑形状,获得了光斑尺寸的放大倍数,验证了AOD对飞秒激光的光斑畸变效应.
The light spot distortion effect of femtosecond laser pulses propagating through an acousto-optical deflector (AOD) was analyzed. Because of wide spectrum bandwidth of the mode-locked laser, When the AOD works, the light spot of the 1st diffraction order will be distorted by significant angular dispersion, thus reduces the spatial resolution of the image. With femtosecond laser passing through the AOD that works at different acoustic frequencies, the shape and size of light spots were recorded, demonstrated the spot distortion properties.