摘要
采用热压印法制备As_(2)S_(3)硫系脊型光波导过程中,波导表面会出现析晶及脱模时黏连问题,难以获得高质量的波导。为此,在As_(2)S_(3)硫系薄膜上蒸镀一层厚约70 nm的具有较高玻璃转化温度的Ge_(20)Sb_(15)Se_(65)硫系薄膜作为覆盖层,实验发现该覆盖层能抑制As_(2)S_(3)硫系脊型光波导表面退化现象,且能解决脱模时的黏连问题,获得质量良好的完整的硫系脊型光波导。利用此覆盖层,优化制备工艺参数,实验制备了脊宽约为4μm、脊高约为950 nm的As_(2)S_(3)硫系脊型光波导,具有完整的波导轮廓,其传输损耗约为0.48 dB/cm@1550 nm。
Low-loss chalcogenide optical waveguide is the key basis of chalcogenide integrated photonic devices.At present,the traditional lithography and etching techniques are mainly used to prepare chalcogenide optical waveguide,but chalcogenide glass is easily corroded by alkaline solution and plasma gas during the etching process,which makes it difficult to control the size and shape of the waveguide,and deteriorates the roughness of the waveguide sidewall and surface.Hot stamping technology is a novel technique for preparing nano or submicron scale structures,which is particularly suitable for use in chalcogenide glass film materials with low glass transition temperature.The sidewall and surface of ridge optical waveguide prepared by this method are smoother,thereby reducing surface light scattering and transmission loss.In this paper,As_(2)S_(3)chalcogenide ridge optical waveguide was prepared by hot stamping method.Through the experiment,it is found that only shallow indentation appeared on the chalcogenide film when the thermoplastic temperature was near the glass transition temperature of As_(2)S_(3)chalcogenide glass(197℃).In order to better fill the mold with the chalcogenide film,the thermoplastic temperature should be increased to 250℃.However,the surface of the As_(2)S_(3)waveguide prepared at the high thermoplastic temperature will have a large number of crystallization and adhesion problems during demolding,resulting in poor surface quality and incomplete profile of the waveguide,and making it difficult to obtain high quality As_(2)S_(3)chalcogenide ridge optical waveguide.By depositing a layer of Ge_(20)Sb_(15)Se_(65)chalcogenide film with thickness of about 70 nm on the As_(2)S_(3)chalcogenide film as a covering layer,the surface degradation of the waveguide layer is inhibited by means of the similar topological connection of chalcogenide glass and the excellent thermal stability of Ge_(20)Sb_(15)Se_(65).And the simulation results show that after adding the covering layer,the energy of the basic mode optical field is mainly concentrated in the As_(2)S_(3)waveguide layer,and the optical field in the covering layer area is weak,so the influence of the covering layer on the optical field can be ignored.The experimental results show that a complete waveguide profile can be obtained under the action of Ge_(20)Sb_(15)Se_(65)covering layer at a thermoplastic temperature of 290℃.This thermoplastic temperature can maintain the low viscosity of As_(2)S_(3)chalcogenide film to fully fill the mold,and also soften the Ge_(20)Sb_(15)Se_(65)covering layer to easily shape a complete waveguide profile.In addition,in order to obtain high quality waveguide profile after hot stamping,the demolding temperature is also an important parameter affecting the quality of waveguide.The experiments show that too low or too high demolding temperature will increase the difficulty of demolding,resulting in incomplete surface of chalcogenide films.Continuously optimizing the preparation process parameters through extensive experiments,the As_(2)S_(3)chalcogenide ridge optical waveguide with ridge width of 4μm and ridge height of 950 nm was prepared with a 70 nm thick Ge_(20)Sb_(15)Se_(65)chalcogenide film covering layer under the hot stamping process with thermoplastic temperature of 290℃,pressure of 0.5 MPa,hot pressing time of 8 min and demolding temperature of 140℃,exhibiting complete waveguide morphology.The experiment shows that this covering layer can effectively inhibit the degradation of the As_(2)S_(3)chalcogenide film during the hot stamping process,and solve the adhesion problem during demolding.By using the cut-back method to measure the insertion loss and linear fitting,the transmission loss of As_(2)S_(3)chalcogenide ridge optical waveguide is about 0.48 dB/cm@1550 nm,indicating that the prepared As_(2)S_(3)chalcogenide ridge optical waveguide with Ge_(20)Sb_(15)Se_(65)covering layer has low transmission loss.These works provide a new method for preparing low-loss chalcogenide integrated photonic devices.
作者
胡海
邹林儿
章玉峰
彭玉发
商俊杰
沈云
HU Hai;ZOU Liner;ZHANG Yufeng;PENG Yufa;SHANG Junjie;SHEN Yun(School of Physics and Materials Science,Nanchang University,Nanchang 330031,China)
出处
《光子学报》
北大核心
2025年第2期165-172,共8页
Acta Photonica Sinica
基金
国家自然科学基金(No.62165008)
江西省自然科学基金(No.20212ACB201007)
江西省研究生创新专项资金(No.YC2023-S091)。
关键词
集成光学
脊型光波导
热压印技术
硫系玻璃
覆盖层
Integrated optics
Ridge optical waveguide
Hot stamping technology
Chalcogenide glass
Covering layer
