Department of Physics, Yale University, New Haven, Connecticut 06511, USA.
1] Department of Physics, Yale University, New Haven, Connecticut 06511, USA [2] Department of Applied Physics, Yale University, New Haven, Connecticut 06511, USA.
Nat Commun. 2015 Feb 24;6:6232. doi: 10.1038/ncomms7232.
Cavity optomechanics offers powerful methods for controlling optical fields and mechanical motion. A number of proposals have predicted that this control can be extended considerably in devices where multiple cavity modes couple to each other via the motion of a single mechanical oscillator. Here we study the dynamic properties of such a multimode optomechanical device, in which the coupling between cavity modes results from mechanically induced avoided crossings in the cavity's spectrum. Near the avoided crossings we find that the optical spring shows distinct features that arise from the interaction between cavity modes. Precisely at an avoided crossing, we show that the particular form of the optical spring provides a classical analogue of a quantum non-demolition measurement of the intracavity photon number. The mechanical oscillator's Brownian motion, an important source of noise in these measurements, is minimized by operating the device at cryogenic temperature (500 mK).
腔光机械学为控制光场和机械运动提供了强大的方法。许多方案预测，在通过单个机械振荡器的运动将多个腔模耦合在一起的设备中，这种控制可以得到极大的扩展。在这里，我们研究了这种多模光机械装置的动态特性，其中腔模之间的耦合来自腔谱中机械诱导的避免交叉。在避免交叉附近，我们发现光学弹簧具有明显的特征，这些特征来自腔模之间的相互作用。在避免交叉处，我们证明了光学弹簧的特殊形式提供了对腔内光子数的量子非破坏测量的经典模拟。在这些测量中，机械振荡器的布朗运动是噪声的一个重要来源，通过在低温（500mK）下操作设备，可以将其最小化。
