Optimizing Wavelength for Enhanced Cycling Durability of Laser‐Induced Phase Change in Sb<sub>2</sub>S<sub>3</sub> Films: A Survey on Optical Transmission Phase Shift
Kun Gao, Feifan Qiang, Senmao Tian, Yu Tan, Siyuan Liu, Wending Zhang, Ting Mei
Abstract
Abstract The advancement of nonvolatile reconfigurable photonic elements has led to the development of Sb 2 S 3 as a desirable phase change material for optical phase modulation in visible and near‐infrared wavebands. However, achieving long‐lasting cycling durability of the phase change remains a formidable challenge. Traditional characterization methods like transmittance or reflectance measurement fail to provide a quantitative assessment of the degree of phase change. To address this, the study focuses on enhancing the cycling durability of complete phase change in Sb 2 S 3 films by manipulating the wavelength of a femtosecond laser for amorphization. To accurately measure optical transmission phase shifts during phase change experiments, a novel liquid‐crystal retardance matching technique based on the Mach–Zehnder interferometer is developed. This approach allows for a direct and quantitative assessment of the degree of phase change without relying on an optical model. The findings reveal that longer wavelengths and multi‐pulse irradiation with increasing pulse energy significantly enhance the cycling durability of the phase change. Additionally, the cost‐effective customization of nonvolatile photonic elements is demonstrated using laser direct writing, eliminating the need for lithography. It is anticipated that this work will drive advancements in Sb 2 S 3 ‐based reconfigurable devices and contribute to the broader field of nonvolatile reconfigurable photonic elements.