Holographic femtosecond laser processing system with an adaptive control

Abstract

Holographic femtosecond laser processing is very useful for high-speed processing with low-loss of light. One of important subjects is to design a computer-generated hologram (CGH) with good performance in the processing system. We have proposed a CGH is optimized in the processing system. The latest method is the SH optimization method based on parallel SH generation. The SH method automatically incorporates the pulse duration and spatial beam profile into the CGH, and therefore gives high quality parallel laser processing. Because of the enhanced processing accuracy, smaller structures are processed with the smallest energy. We demonstrate the 18 parallel laser pulses performs the parallel processing on a glass surface with the average diameter of 271nm under the average fluence of 0.88 J/cm 2 .