Diffractive multi-beam surface micro-processing using 10ps laser pulses
2009; Elsevier BV; Volume: 255; Issue: 22 Linguagem: Inglês
10.1016/j.apsusc.2009.06.089
ISSN1873-5584
AutoresZheng Kuang, Walter Perrie, Dun Liu, Stuart Edwardson, Jian Cheng, Geoff Dearden, K. G. Watkins,
Tópico(s)Nonlinear Optical Materials Studies
ResumoA high repetition rate picosecond laser system is combined with a spatial light modulator (SLM) for diffractive multiple beam processing. The effect of the zero order beam is eliminated by adding a Fresnel zone lens (FZL) to defocus the un-diffracted beam at the processing plane. Chromatic dispersion, which is evident with a large bandwidth femtosecond pulses leading to the problem of distorted hole shape is eliminated due to the much narrower spectral bandwidth, ∼0.1 nm at 10 ps pulselength, resulting in highly uniform intensity spots, independent of diffraction angle. In addition, high-throughput processing is demonstrated by combining the high power laser output, 2.5 W at λ ≈ 1064 nm and fast repetition rate, f ≈ 20 kHz with P > 1.2 W diffracted into 25 parallel beams. This has the effect of creating an “effective” repetition rate of 500 kHz without restrictive scan speeds.
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