Characterization of squeezed states with controllable coherent light injection at sidebands

The squeezed state was experimentally produced in the four wave mixing process for the first time thirty years ago[1].Its intrinsic nonclassical property has always attracted the attention of the scientists,and it has also presented an unpredictable application potential in quantum information processing[2-6]and quantum metrology[7-9].For gaining an insight into the quantum state,Bertrand et al.[10]introduced the concept of quantum tomography into quantum mechanics in 1987.And in 1997,Breitenbach et al.[11]presented the noise distribution of the squeezed states of light fields and reconstructed the quantum states by balanced homodyne detection(BHD).If the squeezed state light field has a relatively strong amplitude,BHD is not suitable.Consequently,other approaches have also been studied,such as self-tomography of the twin-beam state[12]and self-

The squeezed state was experimentally produced in the four wave mixing process for the first time thirty years ago [1]. Its intrinsic nonclassical property has always attracted the attention of the scientists, and it has also presented an unpredictable application potential in quantum information pro- cessing [2-6] and quantum metrology [7-9]. For gaining an insight into the quantum state, Bertrand et al. [10] intro- duced the concept of quantum tomography into quantum mechanics in 1987. And in 1997, Breitenbach et al. [11] pre- sented the noise distribution of the squeezed states of light fields and reconstructed the quantum states by balanced homodyne detection （BHD）. If the squeezed state light field has a relatively strong amplitude, BHD is not suitable. Consequently, other approaches have also been studied, such as self-tomography of the twin-beam state [12] and selftomography of the single-mode squeezed light field with an empty cavity [ 13]. These approaches enable people to understand the nature of the quantum state.