Study On The Perfect Optomechanically Induced Transparency In Multi-mode Systems

Cavity optomechanics is a new subject which studies the interaction between optical field and macroscopic mechanical oscillators.In recent years,thanks to the progress of micro-nano manufacturing technology,cavity optomechanics has been developed rapidly both theoretically and experimentally.The appearance of optical microcavities and mechanical resonators with high quality factors provides the necessary conditions for the observation of quantum effects in optomechanical systems.Cavity optomechanics has potential applications in many aspects,such as the high precision measurement of weak signals,and the realization of non-classical states of optical and mechanical oscillators,such as entangled states and squeezing states.In addition,cavity optomechanical systems can also be used as the interface between coherent light and matter to combine the incompatible degrees of freedom of different physical systems for quantum information processing.At the same time,cavity optomechanics also provides a possibility for the study of quantum phenomena in macroscopic systems.First,we investigate the slow light and optomechanically induced amplification in a coupled cavity optomechanical systems(the standard single-cavity optomechanical system coupled with an auxiliary cavity).Under the condition of perfect optomechanically induced transparency in the system,we find that the slow light can be easily achieved at the perfect transparent window,and if the auxiliary cavity with high quality factor is used,the slow light in the system can easily exceed the upper bound of slow light in the single-cavity optomechanical system.Moreover,if the mechanical damping rate is much less than the dissipation rate of the auxiliary cavity,the slow light will be independent of the frequency of the mechanical resonator.Interestingly,even if the system is driven with mechanical red detuning,the optomechanically induced amplification can still be achieved if a high-quality factor auxiliary cavity is used.More importantly,the maximum magnification is independent of the mechanical damping rate which only affects the width of the output spectral line.In addition,when the system parameters meet a certain condition,the phenomenon of perfect optomechanically induced absorption in the system can appear.We also theoretically investigate the phenomena of perfect optomechanically induced transparency,slow light and optomechanically induced absorption in a multi-mode optomechanical system(consisting of two optical cavities and a mechanical oscillator).Firstly,we give the conditions for the perfect optomechanically induced transparency of the system.And as long as this condition is satisfied,the perfect optomechanically induced transparency can be achieved even with a large mechanical damping rate,which is difficult to be achieved in the previous theory of optomechanically induced transparency,because the depth of the transparent window will be very shallow due to the large damping rate of mechanical oscillator.We also find that the dispersion curve becomes very steep in the perfect transparent window,which means that the ultra-slow light can be achieved there.In addition,the driving intensity and dissipation rate of the second cavity have great influence on the properties of optomechanically induced absorption.In particular,the conversion between perfect optomechanically induced transparency and optomechanically induced absorption can be easily achieved just by adjusting the driving intensity of the second cavity.Using this property,the system can be used as an optical switch in modern optical networks.We believe that these results can be applied to quantum information processing and optical transmission control in modern optical networks.