Photon Statistics Of Optical Parametric Oscillator Far Below Threshold

The non-classical photon statistics with narrow-bandwidth plays an important role in quantum information processing, such as quantum cryptography, quantum teleportation, quantum computation, ghost imaging, and so on. Spontaneous parametric down-conversion (SPDC) process can be used to prepare many kinds of quantum states, such as entangled states and single photon states, but in general the bandwidth is too large to be used for the interface between the photons and atoms.In contrast to the SPDC with large bandwidth, optical parametric oscillator (OPO) could be used for the generation of narrow bandwidth non-classical field. Usually, in OPO the bandwidth of the emitted photons is limited only by the cavity bandwidth. In the case of weak pump, the generated weak photon pairs will be super-bunched with the second order degree of coherence g(2) much higher than that of the chaotic thermal beam (g(2)=2 for thermal light). Such super-bunched light is non-classical and can be used for quantum storage and retrieval in quantum information science.The main works of this dissertation are as follows:1. Photon statistics of the weak squeezed vacuum field from an OPO operating far below the threshold is investigated. We discuss the second correlation function of the multi-mode two-photon states from the OPO.2. In experiment, the frequency doubler and the OPO are optimized. Conversion efficiency of the frequency doubler is about 40%.3. The second order degree of coherence of the multimode two-photon pairs in the OPO far below threshold is studied by means of the HBT scheme, and the result is consistent with theoretical analysis.4. The proposal of generating the narrow-bandwidth single photon source and photon-subtracted states are presented based on the present experimental system.