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Laser Generated Ripple Patterns on Dielectrics and Intermediate Band Gap Semiconductors Pages: 10 Published: Jan 1986
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View License Agreement In this paper we report the results of studies of laser generated ripple patterns on intermediate band gap semiconductors (e.g., ZnS, ZnSe) and dielectrics of various indices of refraction by 10.6 μm laser pulses. The results confirm, only on a coarse scale, the scenario of the formation of coherent structures on the front or rear surface of damaged materials. In particular, for a variety of transparent dielectrics, we carefully determined the ripple spacing through microscopic observation and by diffraction pattern measurements. The ripple spacing and direction are consistent with prior observation by other workers. Similar measurements on front and rear surfaces of ZnS and ZnSe were also carried out revealing the presence of domains of regularly spaced ripple formations and fine structures superimposed parallel to the main pattern. Such fine structures are also present in the damaged dielectric samples, although they are perpendicular to ripple direction. Furthermore a “wrong” orientation, i.e., parallel to the incident field, of the induced gratings was observed. This points toward a less naive interpretation of laser induced ripples than has been described in the literature thus far. | ||
