Chalcogenide based micro-devices, including integrated photonic waveguides and metasurfaces, have broad applications from mid-infrared nonlinear optical signal processing to reconfigurable photonic metasurfaces. Laser machining is a flexible and cost-effective method for lithography-free patterning and postprocessing of large scale microphotonics. In the past, patterning of chalcogenide thin film materials has been focused on dosage studies with single-point laser exposure, or laser inscription of waveguides. Little effort has been made to find how to reduce feature size or improve the optical qualities of the pattern. In this work, we use a nanosecond laser to create linear features with high refractive index contrast in chalcogenide glass thin film and compare the feature size and surface roughness to other dielectric and metal thin films. By tuning laser power and burst pulse numbers, a minimal feature size of 6 µm and edge roughness of 3 nm can be achieved in chalcogenide phase change material thin film. Non-volatile tunabilities are demonstrated in those laser-patterned microphotonic gratings.

中文翻译：

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平面硫属化物微光子学的亚带隙脉冲激光图案化

基于硫属化物的微器件，包括集成光子波导和超表面，具有从中红外非线性光信号处理到可重构光子超表面的广泛应用。激光加工是一种灵活且具有成本效益的方法，可用于大规模微光子学的无光刻图案化和后处理。过去，硫族化物薄膜材料的图案化一直专注于单点激光曝光或波导激光刻字的剂量研究。几乎没有努力寻找如何减小特征尺寸或提高图案的光学质量。在这项工作中，我们使用纳秒激光在硫属化物玻璃薄膜中创建具有高折射率对比度的线性特征，并将特征尺寸和表面粗糙度与其他电介质和金属薄膜进行比较。通过调整激光功率和突发脉冲数，可以在硫族化物相变材料薄膜中实现 6 µm 的最小特征尺寸和 3 nm 的边缘粗糙度。在那些激光图案化的微光子光栅中展示了非易失性可调性。