真空光镊中纳米粒子的参数反馈冷却实验研究  

Experimental study on parametric feedback cooling of nanoparticles in vacuum optical tweezers

作　　者：苏琛 胡绍民[1,2] 曹慧杰 韩翔 肖光宗 罗晖[1,2] SU Chen;HU Shaomin;CAO Huijie;HAN Xiang;XIAO Guangzong;LUO Hui(College of Advanced Interdisciplinary Studies,National University of Defense Technology,Changsha 410073,China;Nanhu Laser Laboratory,National University of Defense Technology,Changsha 410073,China)

机构地区：[1]国防科技大学前沿交叉学科学院,湖南长沙410073 [2]国防科技大学南湖之光重点实验室,湖南长沙410073

出　　处：《计测技术》2024年第4期71-78,共8页Metrology & Measurement Technology

基　　金：湖南省重大科技攻关项目(2023ZJ1010);湖南省自然科学基金项目(2021JJ40679)。

摘　　要：为了解决真空光镊中粒子稳定捕获等问题,开展了参数反馈冷却纳米粒子质心运动的实验研究,在单光束真空光镊系统中,成功实现了3 mPa气压下直径为200 nm SiO-2粒子的稳定捕获和等效冷却。比较了拟合曲线延伸法、拟合曲线截取法和真实曲线截取法的特点,选取真实曲线截取法评估纳米粒子的等效冷却温度。实验结果表明,粒子单轴质心运动等效温度最低被冷却至约390 mK,相应的力测量极限噪声水平大约降低至原先的3.6%。研究成果为实现基于真空光镊技术的超高灵敏度物理量测量提供了重要参考。In order to solve the problem of stable trapping of particles in optical tweezers in vacuum,experimental research on parameter feedback cooling of nanoparticle's center⁃of⁃mass motion was conducted.In a single beam vacuum optical tweezers system,stable capture and equivalent cooling of SiO2 particles with a diameter of 200 nm under 3 mPa pressure were successfully achieved.Several methods for equivalent temperature estimation were compared,including the integral method using the extension based on the fitted power spectral density curve(PSD),the integral method using the truncation based on the fitted PSD curve,and the integral method using the truncation based on the real PSD curve.The last method was selected to evaluate the equivalent cooling temperature of nanoparticles.The experimental results show that the equivalent temperature of the nanoparticle's center⁃of⁃mass motion in single axis is cooled to approximately 390 mK in minimum,and the corresponding thermal noise limit can be reduced to about 3.6%of its original value in the ultra⁃weak force measurement.The research results provide valuable references for the ultra⁃high sensitivity measurement of physical quantities based on optical tweezers in vacuum.

关 键 词：真空光镊 纳米粒子 参数反馈冷却 等效冷却温度评估 

分 类 号：TB9[一般工业技术—计量学] O439[机械工程—测试计量技术及仪器] TN247[机械工程—光学工程]