Nonclassical State Via Superposition Of Two Coherent States Pi/4 Out Of Phase With Each Other And Related Entangled States

The graduation design begins with the basic concept including Heisenberg uncertainty relation, the vacuum state and coherent state, gradually researching the definition and characteristics of the single.mode squeezed coherent state, squeezed vacuum state and amplitude squeezed state. With the study of the interaction of coherent light and squeezed light and research of two squeezed light, we found that if we superpose a coherent light and a squeezed light with different amplitudes but the same phase, the properties of new waves must be compressed.In another words, the photo in the output signal to maintain quantum correlation property.We also discuss the characteristics via superposition of two coherent states (pi/4 out of phase).The squeezing regions are located in the valley parts of the curved surface, with different size and position according to different ?.The squeezing region contains the states satisfying the inequality along the line of x1=x2 and the neighborhood in phase space;for the increasing |?|2, it becomes thinner but does not fade out, and eventually a series of segments on the line of ?1,= ?2 remain.No squeezing in the operator X2 occurs in the areas far from the line of ?1= ?2.If there exists values of ? and ? for which ?< 1 and the inequality ?< 1 and ?j<0 are both satisfied, the state |?) exhibits sub.Poissonian statistics and and quadrature squeezing coincidently.In the case of exhibit squeezing for any nonzero value of ? providing |x|=|x2|, whereas no squeezing occurs in the state In comparison with the case of the state|?>, the squeezing region of the state in phase space is extended.