Versatile Quantum State Engineering By Quantum Interference

Interference between independent photon sources is the key to realizing complex quantum systems for quantum information technology applications,such as multiphoton entanglement generation and quantum teleportation.For the photon sources prepared through nonlinear parametric process,engineering the joint spectral function(JSF)effectively is required to eliminate the frequency/time correlation between the signal and idler photons,which is benefit to improving the visibility of photon interference.So far,there are two methods to engineer the JSF.One is using narrow-band spectral filter and the other is controlling the dispersion parameters of the nonlinear media.Although the former is a simple and effective way,the photon collection efficiency is reduced accordingly due to the destruction of the original JSF.The latter relies on the dispersion and length of nonlinear media,as well as the bandwidth of pump,which lead to the lack of flexibility.In this thesis,a new versatile and precise approach based on the quantum interference is proposed and investigated,which is helpful to promoting the performances of quantum sources based on the spontaneous parametric process.First of all,as a theoretical basis,the mode properties of multimode two-photon states and heralded single-photon states are characterized through Schmit mode decoposition,and the key parameters such as state purity and heralding efficiency are defined.Secondly,engineering the JSF by quantum interference realized in nonlinear interferometer(NLI)is proposed and analyzed theoretically.Based on the two-stage fiber structured NLI,the improving of second-order correlation function and collection efficiency comparing to the non-NLI case are demonstrated experimentally.And then,in order to reveal the influence of Raman noise on four wave mixing fields in intensity correlation measurement,the interference between two independent multi-temporal mode thermal fields is studied theoretically and experimentally.Finally,a high purity C-band heralded single photon source is realized based on the micro/nano fiber and a wavelength tunable source of correlated photon pairs is demonstrated experimentally using photonic crystal fiber,all of which pave the way for applying quantum interference in micro/nano fiber and photonic crystal fiber system to prepare the low Raman noise quantum source with large frequency tuning ability.The main innovations are as follows.First,using quantum interference to engineer the JSF is proposed for the first time and studied both theoretically and experimentally.Second,the interference between independent multi-temporal mode thermal field is revealed by measuring the intensity correlation after mixing the two independent fields.Third,based on the micro/nano fiber and photonic crystal fiber,a low Raman noise heralded single photon source and a wavelength tunable correlated photon pairs source are experimentally demonstrated,respectively.