用于压缩态产生的低损耗氮化硅微环谐振腔制备及测试  

Experimental Study on Low-loss Silicon Nitride Micro-ring Resonators for Generation of Squeezed States

作　　者：白捷仁 周笑艳 郭学石 李小英 张林[1] BAI Jieren;ZHOU Xiaoyant;GUO Xueshi;LI Xiaoying;ZHANG Lin(School of Precision Instruments and Opto-electronics Engineering,Tianjin University,Tianjin 300072,China)

机构地区：[1]天津大学精密仪器与光电子工程学院,天津300072

出　　处：《量子光学学报》2025年第1期25-32,共8页Journal of Quantum Optics

基　　金：国家自然科学基金(62005195)。

摘　　要：集成光子芯片为压缩态光场的产生提供了一个可靠和易于扩展的平台。基于低损耗氮化硅微环谐振腔的四波混频过程是产生压缩态光场的重要途径。本文基于氮化硅材料平台,优化了高质量氮化硅薄膜的制备工艺和微环谐振腔的加工过程,制备出多种尺寸和结构的低损耗氮化硅微环谐振腔。通过搭建的测试系统,系统分析了这些微环谐振腔的透射率、耦合状态和品质因子。实验结果表明,所制备的微环谐振腔具有稳定的本征品质因子,其中横截面尺寸为2000 nm×290 nm微环谐振腔的本征品质因子可达1.5×10^(6),对应的波导传输损耗约为0.23 dB/cm。理论计算表明,该结构最优能够产生片上约9 dB的压缩态光场,当考虑总检测效率为40%时,预估可以直接观察到2 dB的压缩态。该研究为片上产生高质量的连续变量压缩态提供了实验基础。Objective Squeezed states are an important resource in quantum information processing.Utilizing squeezed light can enhance the sensitivity of physical measurements and surpass the standard quantum limit,making it an indispensable element in quantum information science.Integrated photonics chips provide a reliable and easily scalable research platform for generating squeezed states,and the high stability and reproducibility of modern lithographic techniques offer hope for achieving large-scale quantum technologies.The four-wave mixing process based on silicon nitride micro-ring resonators is an important approach for generating squeezed states.The main factors limiting the generation of on-chip high-level-squeezing include micro-ring resonator design,nonlinear noise,and,especially,photonic loss.To further improve the level of squeezing generated on-chip,the preparation of low-loss or high-Q silicon nitride micro-ring resonators is particularly crucial.Methods In this work,we employed low-pressure chemical vapor deposition(LPCVD)to deposit high-quality silicon nitride films.To achieve micro-ring resonators with varying states of coupling,we designed a series of micro-ring resonators with different coupling gaps.Using scanning electron microscopy,we optimized both the deposition process of high-quality silicon nitride films and the etching process of micro-ring resonators on the silicon nitride platform.As a result,we successfully fabricated lowloss silicon nitride micro-ring resonators with various sizes and structures.We also set up a testing system for the micro-ring resonators,using lensed fibers for end-face coupling with the chip.Then,we experimentally characterized these micro-rings and systematically analyze their transmission spectra,coupling regimes,and quality factors.Results and Discussions Results show that the prepared micro-ring resonators have similar intrinsic quality factors.Notably,the intrinsic quality factor of the micro-ring resonator with a cross-sectional size of 2000 nm×290 nm reaches 1.5x1

关 键 词：集成量子光学 微环谐振腔 压缩态 

分 类 号：O431.2[机械工程—光学工程] TN491[理学—光学]