Theoretical And Experimental Study Of The Generation And Application Of Correlated Photon-pairs From Spontaneous Four-wave Mixing In Optical Fibers

Quantum correlated photon pair sources are not only the important resources for fundamental test of quantum mechanics, but also crucial for quantum information processing and quantum metrology. Based on spontaneous four-wave mixing in dispersion shifted fibers, near-degenerated quantum correlated photon pairs are generated by pulsed pump, and the characteristics and applications of photon pairs are theoretically analyzed and experimentally demonstrated. The main contents include the following four aspects:1,The theoretical model of spontaneous four-wave mixing in optical fibers is established. To the best of our knowledge, we derive the field operator evolution equation for chirped pump pulses for the first time in the Heisenberg picture, which satisfys the Bogoliubov transformation. Differently from the commonly used quantum state evolution equation in the Schrodinger picture, the field operator evolution equation is not only suitable to study the quantum correlated photon pairs in the low gain regime, but also in the high gain regime. The field operator evolution equation lays a theoretical foundation for the study of quantum properties of photon pairs.2,The quantum correlation property of photon pair and its application in quantum efficiency measurement of single photon detectors are investigated. Based on the field operator evolution expression, the dependence of quantum correlation on the spectra of pump, signal, and idler photons is studied. After analyzing the spectral property and the bunching effects of photon pairs, with carefully exclusion of noise photons from other nonlinear effects, such as self-phase modulation of pump pulses and spontaneous Raman scattering in optical fiber, the quantum efficiency of single photon detector is measured by using photon pairs with various kinds of bandwidths; therefore it is also useful for accurately characterizing the photon pairs.3,The effect of chromatic dispersion induced chirp on the temporal mode property of individual singal (idler) beam generated from spontaneous emission is theoretically studied and experimentally demonstrated. The investigation includes the influence of pump chirp on the temporal coherence of individual signal (idler) beam, and the influence of the chirps of individual beams on the tempral mode matching in fourth-order quantum interference between independent fields. This study is useful for improving the interference visibility in fourth-order quantum interference between independent fields, and for quantum computing and quantum teleportation.4,The methods for generation and verification of frequency entangled photon pairs are introduced, and the expression of interference visibility in high gain regime is deduced by using the field operator evolution equation. The reasons of reducing the interference visibility are analyzed, and the relation between the interference visibility and the coincidence to accidental coincidence ratio of signal and idler photons is established. The investigations are useful for optimizing the entangled photon sources.