Programmable photon pair source

Abstract

Photon pairs produced by the pulse-pumped nonlinear parametric processes have been a workhorse of quantum information science (QIS). Engineering the spectral property of quantum states is crucial for practical QIS applications. However, photon pairs with desirable spectral properties are currently achieved with specially engineered optical hardware but with severely limited flexibility in tuning the spectral properties of the sources. Here, we demonstrate a spectrally programmable photon pair source by exploiting a two-stage nonlinear interferometer scheme with a computer-controlled phase device. The phase-control device can introduce phase shifts for spectral engineering by a programmable phase function that can be arbitrarily defined. When the phase function is properly designed, the output spectrum of the source can be freely customized and changed without replacing any hardware component in the system. Using this approach, we are able to program photon pairs with factorable positively correlated and negatively correlated spectra. In addition, we also realize a source of multi-dimensional three-channel spectrally factorable photon pairs. Our investigation provides a flexible and powerful new approach for engineering the mode profile of photon pairs and should find wide applications in QIS.

Entangled photons enabled ultrafast stimulated Raman spectroscopy for molecular dynamics

“…However, the experimental methods were developed recently to engineer the spectral correlation by certain design 54 – 56 . In particular, the spectral correlation property required in our scheme, i.e., frequency positively correlated twin photons, has been achieved in experiments 55 , thus paving the road for the Raman spectroscopy application. The basic strategy was a clever integration of nonlinear interference scheme and phase-control device, in which the former was made by a group of nonlinear mediums with the parametric down conversion involved 57 , 58 .…”

“…The basic strategy was a clever integration of nonlinear interference scheme and phase-control device, in which the former was made by a group of nonlinear mediums with the parametric down conversion involved 57 , 58 . The spectral function of the photon pairs can be further modulated by the phase-control devices, leading to the programmable spectral properties of the photon pairs 55 . Further experimental endeavor on the Raman spectroscopy with the entangled photons is under way and will be presented in near future.…”

“…There were several quantum-optical experiments which had demonstrated the independent time and frequency scales in the entangled photons 54 , 55 . These experimental observations—by presenting a variety of advantages and superiority through a diversity of systems including atoms and qubits—are intimately connected to the Q-USRS.…”

Polarization-entangled photon pairs with factorable spectra engineered by using an uneven four-stage nonlinear interferometer

“…To engineer the mode structure of the quantum states, it has been proposed that precise state engineering for near ideal single mode operation and near unity efficiency can be achieved by using SU(1,1) nonlinear interferometers (NLIs) [19][20][21] . Since the interferometric method separates the spectral control from the phase matching of the nonlinear process, photon pairs simultaneously possess the features of high purity and high collection efficiency, and high flexibility in wavelength and bandwidth selection can be generated.…”