基于高重复频率飞秒激光直写技术制作衍射光栅的研究

基于由光子晶体光纤飞秒激光器产生的高重复频率飞秒激光搭建了飞秒激光微加工系统,利用LabVIEW编写程序精密控制三维移动平台的移动路径和高速快门,在加工功率为1.5W、移动速率为1mm/s时,利用直写技术在无胶铬版上得到了微米量级的任意形状的平面衍射光栅。利用CCD相机对光栅制备过程进行实时监视,保证了光栅的加工质量。制备的光栅在显微镜下观察,条纹边缘清晰、线纹粗细均匀。使用He-Ne激光照射加工的光栅,可以获得清晰、稳定、与理论符合很好的夫琅和费(Frauhofer)衍射图样,显示了所加工的光栅具有良好的光学性能。实验结果也表明了光子晶体光纤飞秒激光在光栅制作过程中所具备的良好的加工性能。

Diffraction gratings fabricated by high repetition rate femtosecond laser pulses direct writing technique

Based on femtosecond photonic crystal fiber laser,a micro-processing system is built.By precise control-ling the motion path of three-dimensional translation platform and high-speed shutter with LabVIEW language,when the laser power is 1.5W,scanning speed is 1mm/s,arbitrary shape micrometer level diffraction gratings are fabricated on no photoresist chrome mask.In order to ensure quality of the fabricated grating,the machining process is monitored real-time using a CCD camera.Under a microscope,it is found that the fabricated gratings have clear edges,uniform thick-ness.Under illumination of a He-Ne laser beam,the Fraunhofer diffraction patterns of the fabricated gratings are clear, stable and consistent with theoretical analysis,which show that the fabricated gratings have good optical property.The experiment results show that the femtosecond photonic crystal fiber laser have excellent laser machining performance.