%A ZHANG Yun %T Generation of non-classical states from an optical parametric oscillator/amplifier and their applications %0 Journal Article %D 2008 %J Front. Phys. %J Frontiers of Physics %@ 2095-0462 %R 10.1007/s11467-008-0018-y %P 126-152 %V 3 %N 2 %U {https://journal.hep.com.cn/fop/EN/10.1007/s11467-008-0018-y %8 2008-06-05 %X Quantum information and quantum optics are rapidly advancing areas of modern physics. As an important device in quantum optics and quantum information, the optical parametric amplifier/oscillator (OPA/O) has been extensively studied and applied to the generation of non-classical state since the 1980s. This article reviews the progress in the generation of non-classical state from an OPO/A and application of twin beams in quantum optics and quantum information.