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 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.

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-