Advanced Manufacturing of Chalcogenide Glass Through Femtosecond Laser Processing—From Waveguides to 3D Dimensional Micro-Structures Fabrication

The advanced 3D micro- and nano- structuring of mid-IR material, such as chalcogenide glass, is of high-interest for the fabrication of photonic devices in general, and for spectroscopy applications in particular. Yet, the processing of these materials at microscales remains challenging and limited.<br/>Here, we investigate the use of femtosecond laser for producing arbitrary three-dimensional patterns with varying physical properties in four ternary chalcogenide glass compositions: Ge₂₃Sb₇S₇₀, Ge₂₃As₇S₇₀,Ge₂₃Sb₇Se₇₀, and Ge₂₃As₇Se₇₀.<br/>Interestingly, under specific laser exposure conditions, we observe the occurrence of both, densification and self-organization patterns formation, for which we explore the response to chemical etching. Furthermore, in an attempt to unravel generic laser-induced transformation mechanisms common to the four glass compositions investigated here, we systematically correlate pulse-to-pulse structural changes with material's inner structures evolution, using both, elemental and micro-Raman observations.<br/>These observations emphasize the potential of ultrafast lasers not only for introducing waveguiding properties in chalcogenide glass, but also, for patterning them at the micro-scale.