双拉盖尔-高斯腔光力系统中的腔内压缩冷却研究  

Intracavity-Squeezed Cooling in Double-Laguerre-Gaussian-Cavity Optomechanical System

作　　者：廖庆洪[1] 邱海燕 程绍平 朱泓宇 曾永强 Liao Qinghong;Qiu Haiyan;Cheng Shaoping;Zhu Hongyu;Zeng Yongqiang(Department of Electronic Information Engineering,Information Engineering School,Nanchang University,Nanchang 330031,Jiangxi,China)

机构地区：[1]南昌大学信息工程学院电子信息工程系,江西南昌330031

出　　处：《光学学报》2024年第3期271-279,共9页Acta Optica Sinica

基　　金：国家自然科学基金(62061028);南昌大学江西省财政科技专项“包干制”试点示范项目(ZBG20230418015);上海市特殊人工微结构材料与技术重点实验室开放基金(ammt2021A-4)。

摘　　要：机械振子的冷却是腔光力学研究的重要方向之一。计算光力噪声谱和稳态的最终声子数,对基于耦合光学参量放大器(OPA)的双拉盖尔-高斯腔光力系统中的腔内压缩冷却问题进行研究。在弱耦合条件下,利用微扰近似理论方法得出系统的光力噪声谱,基于费米黄金法则的理论计算出稳态下的最终声子数的解析表达式。利用入射泵浦光驱动腔场内耦合的OPA,使腔场内形成强烈的非线性压缩效应,量子反作用加热过程得到有效抑制,系统净冷却率得到显著提高。此外,讨论了其他系统参数对机械振子冷却的影响。最后研究了系统的稳态声子数,声子数可以在较大参数范围内小于1。该方案能有效地降低机械振子的冷却极限。Objective Cooling of mechanical oscillators is an important direction of cavity optomechanics research.Cooling the mechanical oscillators to their quantum ground state is a prerequisite for a wide range of applications based on cavity optomechanics.Therefore,ground-state cooling of mechanical oscillators is the focus of cavity optomechanics at present,which attracts a large number of scholars to study it.However,due to noise interference from external environments,the mechanical oscillators cannot enter the quantum regime.The hybrid system-coupled optical parametric amplifier provides a unique platform to solve the above problem.Methods The hybrid optomechanical system consists of two fixed mirrors(FM)including a rotational mirror(RM)mounted on the support S which can rotate around the Z axis,and an OPA medium.Cavity 1 which couples the OPA medium is made up of partially transparent FM1 and perfectly reflecting RM while cavity 2 is composed of FM1 and another perfectly reflecting FM_(2).The cavity 1 is driven by the transmitted beam with charge 0 and a Laguerre-Gauss beam(G)of charge 0 is incident on FM1.The charge 0 beam reflected from the RM is charged to+2l and then returns to FM1,where a mode with charge 0 is generated and enters cavity 2.After the reflection of FM_(2),it is also charged to+2l.We study the problem of the intracavity-squeezed cooling in the optical parametric amplifier coupled by a double Laguerre-Gaussiancavity optomechanical system by calculating the optical force noise spectrum and the steady-state final phonon number.In the weak coupling regime,the optical force noise spectrum of the system is obtained by the perturbation approximation method,and the analytical expression of the final phonon number is calculated by the Fermi Golden Rule theory.Results and Discussions When the OPA medium is considered in the hybrid optomechanical system,the heating rate of the optical noise spectrum S_(FF)(ω)atω=-ω_(ϕ)is reduced to 0,with an unaffected cooling rate.In other words,A+drops while A-remains

关 键 词：量子光学 双拉盖尔-高斯腔 基态冷却 腔内压缩 光力噪声谱 

分 类 号：O436[机械工程—光学工程]