Research On Magneto-optical Rotation Based On Spin Coherence And Its Application In Cavity QED System

In recent years,cavity quantum electrodynamics(cavity QED)have attracted considerable interesting in scientific community due to its unique optical properties.It has long been the central paradigm for quantum information processing,as well as the ideal candidate for quantum measurement with high precision accuracy.Owing to the developments in optical microcavity,it is possible to research and design optical devices with cavity QED systems.When the cavity QED system applied in quantum measurement,the collect effect in cavity-atomic ensemble system ensures the high sensitivity.Not only can the magneto-optical rotation(MOR)in cavity QED system be used to detect weak magnetic field with high sensitivity,but also to design optical devices.In this thesis,we mainly investigate the quantum control of MOR in cavity QED system,as well as its potential applications.The main innovative and important results are:1)We investigate theoretically the MOR in cavity QED system with spin coherence.Using realistic experimental parameters we demonstrate,owing to the spin coherence established via coherent population trapping technique,ultranarrow transmission spectral less than 1-MHz with gain can be achieved with a flat-top response associate with Faraday rotation angle.By controlling the parameters appropriately,all input probe frequency components within the flat-top regime rotate with almost same angle,and then transmit through the cavity perpendicularly to the other frequency components outside this regime.2)We investigate the MOR in cavity-quantum dot(QD)molecule system based on spin coherence and intracavity electromagnetically induced transparency.Both the Faraday rotation angle and the transmission strongly depend upon the strength of tunneling of hole between QDs.Our analysis demonstrates that it is possible to sensing the tunneling.