Photon pair-state preparation with tailored spectral properties by spontaneous four-wave mixing in photonic-crystal fiber

Abstract

We study theoretically the generation of photon pairs by spontaneous four-wave mixing (SFWM) in photonic crystal optical fiber. We show that it is possible to engineer two-photon states with specific spectral correlation ("entanglement") properties suitable for quantum information processing applications. We focus on the case exhibiting no spectral correlations in the two-photon component of the state, which we call factorability, and which allows heralding of single-photon pure-state wave packets without the need for spectral post filtering. We show that spontaneous four wave mixing exhibits a remarkable flexibility, permitting a wider class of two-photon states, including ultra-broadband, highly-anticorrelated states.

Nonlinear optical signals and spectroscopy with quantum light

“…It further implies that the two-photon absorption rate scales linearly in the low gain regime, even though the single mode squeezed state does not show time-energy entanglement in the sense of section II.C. An experimental verification thereof is reported in (Georgiades et al, 1995(Georgiades et al, , 1997.…”

“…This allows to carry out microscopy and lithography (Boto et al, 2000) applications at much lower photon fluxes. The different intensity scaling with entangled photons has been first demonstrated in atomic systems by (Georgiades et al, 1995) and later by (Dayan et al, 2004, as well as in organic molecules (Lee and Goodson, 2006). An entangled two-photon absorption (TPA) experiment performed in a porphyrin dendrimer is shown in Fig.…”

“…With entangled photons, such signals scale linearly (Dayan et al, 2004Friberg et al, 1985;Georgiades et al, 1995;Javanainen and Gould, 1990). This allows to carry out microscopy and lithography (Boto et al, 2000) applications at much lower photon fluxes.…”

Conversion efficiency in the process of copolarized spontaneous four-wave mixing

“…which includes a nonlinear contribution (γ 1 P 1 + γ 2 P 2 ) derived from self/cross-phase modulation [6], where γ ν is the nonlinear coefficient given by…”

“…Following the treatment presented in section 2 of Ref. [6] it is possible to find an analytic expression for the conversion efficiency η (N DP below refers to nondegenerate pumps)…”