Quantum optics, which is based on the coherence and quantum of the optics, aims at investigating various non classical effects of light field and the interaction between light and matter by using  the quantum mechanics theory and experimental techniques of modern optics and electronics.
    We obtained variaous different non-classical optical fields by using the non degenerate optical parametric oscillation and amplification, such as two mode squeezed vacuum state, intensity difference squeezed state, bright Einstein-Podolsky-Rosen entangled optical beams, tripartite entangled optical field, four-partite GHZ-like and cluster-like entangled optical field, the TTPC entangled states, and eight-partite cluster entangled states, et al. We accomplished experiments based on the prepared non-classical optical fields, such as weak signal detection with the signal-noise-ratio beyond the standard quantum limit, the quantum nondemolition measurement for intensity difference signal, continuous variable quantum dense coding, controlled quantum dense coding, quantum entanglement swapping, continuous variable quantum key distribution, quantum controlled-X gate, quantum logic gate sequence, et al. Now, we are focused on continuous variable one-way quantum computation and quantum network.