Suppressing Rayleigh Scatter in Levitated Optomechanics

悬浮光学机械使用单个纳米颗粒，在激光焦点处保持在真空中，作为精密测量的平台。国际上的努力现在在于试图利用这些和相关系统达到量子状态，以便用作弱外部扰动（如引力场）的传感器。悬浮纳米粒子是一种有前途的途径，远远超过目前现有技术的敏感性。然而，这些先进的传感应用需要创建大的空间叠加的纳米粒子，这遭受快速退相干。特别是，悬浮粒子受到激光本身的退相干;粒子散射的激光光子随机扰动其运动。该项目的主要目标是证明抑制瑞利散射光作为一个关键的源的消相干悬浮光学力学。要做到这一点，我的目标是设计和构建一个实验，将利用半球镜抑制瑞利散射相消干涉。我也可以探索该系统在高级传感和更基本的问题上的潜在应用，这些问题涉及量子力学定律如何在宏观尺度上运作。

Levitated Optomechanics uses a single nanoparticle, held in vacuum at the focus of a laser, as a platform for precision measurement. International effort now lies in attempting to reach the quantum regime using these and related systems in order to be utilised as sensors of weak external perturbations such as the gravitational field. Levitated nanoparticles are a promising route towards far exceeding the sensitivities of currently existing technologies. However, these advanced sensing applications require the creation of large spatial superpositions of the nanoparticle, which suffers from rapid decoherence. In particular, levitated particles are subject to decoherence from the laser itself; the laser photons which the particle scatters, randomly perturb its motion. The main objective of the project is to demonstrate the suppression Rayleigh scattered light as a key source of decoherence in levitated optomechanics. To do this, I will aim to design and construct an experiment which will utilise a hemispherical mirror to suppress Rayleigh scatter by destructive interference. I may also explore the potential applications of the system to advanced sensing and more fundamental questions regarding how the laws of quantum mechanics operate on the macroscopic scale.