Photon pair sources with controlled frequency correlation

Abstract

Development of efficient and well-controlled nonclassical photon sources is one of the keys in the quantum information and communication technology. We present our recent activities to develop advanced sources of photon pairs having controlled frequency correlation, by use of quasi-phase matching (QPM) and extended phase-matching (EPM). First, we present the generation of polarization and frequency entangled photons using QPM having two poling periods. We also demonstrate the photon pair generation with controlled frequency correlation and its application to making heralded single photons with intrinsically pure spectrotemporal modes.

Simple method of generating and distributing frequency-entangled qudits

“…Quantum state engineering in a PPSLT crystal In this experiment, the SPDC source is based on a periodically poled MgO-doped stoichiometric LiTaO 3 (PPSLT) crystal [18][19][20]42], which has a low birefringence. At 1584 nm, the type II PPSLT crystal satisfies the group velocity matching (GVM) condition of = --…”

“…1 is the inverse of the group velocity for the signal (idler) [20]. Under this GVM condition, the phase-matching function f w w ( ) , …”

Spontaneous parametric down-conversion in asymmetric couplers: Photon purity enhancement and intrinsic spectral filtering

“…in other words when the inverse group velocities are related to each other as β ′ i < β ′ p < β ′ s [32]. However, this is not often possible to achieve in simple waveguide geometries with only few geometrical parameters (such as waveguide width and height) available for dispersion engineering.…”

Spectrally Pure States at Telecommunications Wavelengths from Periodically PoledMTiOXO4(M=Jin1, Zhao2, Deng3 et al. 2016Phys. Rev. AppliedSelf Cite210150View full textAdd to dashboardCite

“…The second method is to engineer the SPDC process, so as to prepare an intrinsically spectrally pure state. Such a quantum state engineering method can be realized by considering the group-velocity-matched (GVM) condition in specific crystals at certain wavelengths [4][5][6]. Previous work in the field has shown that the GVM condition can be realized in several crystals, e.g., KDP crystal at 830 nm [1,2,7], periodically poled KTP crystal (PPKTP) at 1584 nm [5,8] and BBO crystal at 1514 nm [4,9,10].…”