Nonreciprocal Transmission Based On Modulated Optomechanical Systems

VLight itself carries momentum when light irradiates on the surface of an object,momentum will be transferred to the object,and thus produce a force on the object,that is,light radiation pressure.Based on this principle,Braginsky et al.propose the optical mechanic system formed by the coupling of the optical cavity and oscillator through radiation pressure in 1967,which opened a new field of cavity optics.Over the past half-century,researchers have studied the optical force system from the aspects of micro-measurement,optical manipulation,optical storage and so on.In recent years,with the rapid development of nano-technology,the spatial structure size of the optical force system has been gradually reduced,and the quantum effect has become more and more obvious.This makes it possible for researchers to realize long-distance quantum communication and large-scale quantum computing by building a variety of nanoscale quantum devices.Nonreciprocal quantum devices are one of the most important basic components of quantum networks.Through the effective modulation in time and space of the medium,the spatial symmetry of light propagation is broken,and the one-way propagation of light is realized.Nonreciprocal devices can be used to construct unidirectional circulators,isolators,so as to avoid optical dissipation caused by optical interference and other effects,thereby protecting optical signals in transmission.At present,the optical force quantum devices based on radiation pressure coupling have attracted extensive attention of researchers in the field of non-reciprocity due to their high sensitivity and easy manipulation.In order to construct nonreciprocal single-photon optical force quantum devices,we need the coupling strength of optical force system under single-photon to be close to the damping rate of cavity mode,but for a typical optical force system,the coupling strength under single-photon is far lower than the damping rate of the cavity mode.Therefore,how to build the model and find a method to achieve the controllable enhancement of the single-photon optical coupling strength has become the core of this research topic.In this dissertation,first of all,we use the three-mode all-optical Kerr system,through the strong coherent laser drive,to achieve the equivalent simulation of the three-mode optomechanical system,and the single-photon optical force coupling strength enhancement.Afterward,the optimal nonreciprocal transfer condition is derived analytically and simulated numerically,and its applications in circulators and diodes are discussed.Finally,its general theoretical extension to quantum networks is given.