Spatial Controllability of Periodic Ripple Structures Generated in Laser Etching of n-GaAs

Abstract
Spatial controllability of periodic ripple structures was investigated in laser etching of n-GaAs. For single-beam etching and holographic etching with high ratios of average spacing of holographic grating to average spacing of ripple structures (Λhh), ripple structures were observed. In particular, in p-polarization, spatial fluctuation was greater than that in s-polarization. This might occur because phase distortion cannot be eliminated by p-polarization beam irradiation. For holographic etching with small Λhr ratios, ripple structures were changed into grating structures because these grating structures might be generated in phase with holographic gratings.
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