Pattern formation during laser melting of silicon

Silicon films under intense, continuous laser irradiation at λ=10.6 μm develop into spatially inhomogeneous molten states. The systematic study of the different patterns as a function of laser intensity and spot size reveals a variety of ordered and disordered states. For small spot size, highly correlated, long-range periodic structures (gratings) with spatial periods of λ,2λ,3λ,. . . are observed for increasing intensity. For low intensities …