Translation of quantum states by four-wave mixing in fibers

Abstract

Optical frequency conversion by four-wave mixing (Bragg scattering) in a fiber is considered. If the frequencies and polarizations of the waves are chosen judiciously, Bragg scattering enables the translation of individual and entangled states, without the noise pollution associated with parametric amplification (modulation instability or phase conjugation), and with reduced noise pollution associated with stimulated Raman scattering.

Quantum-state-preserving optical frequency conversion and pulse reshaping by four-wave mixing

“…Examples include two-photon energy-time entanglement, the preservation of which was demonstrated in Ref. [3], and polarization entanglement, which is preserved by signal-polarization-independent BS [13].…”

“…Quantum-state-preserving FC is also enabled by four-wave mixing (FWM) in a fiber [13,14]. In the nondegenerate FWM process called Bragg scattering (BS), which is illustrated in Fig.…”

“…where a r and a s are the annihilation operators of the idler and signal, respectively, β r and β s are the group slownesses (inverse speeds), and γ pq (t,z) = γ A p (t − β s z)A * q (t − β r z) is the pump-induced coupling function [13]. These CMEs are based on the assumption that the carrier frequencies and wave numbers are matched.…”

“…If the waves are copolarized and each pump amplitude satisfies the normalization condition |A j (t)| 2 dt = 1, the coupling coefficient γ = 2γ K (E p E q ) 1/2 , where γ K is the Kerr coefficient and E j is a pump energy. The CMEs for cross-polarized waves are similar [13]. The solutions of the CMEs can be written in the input-output form,…”

Spectral photonic lattices with complex long-range coupling

“…Then in a Kerr nonlinear medium, such as optical fiber, a signal can be up-or down-shifted by a multiple of Ω in a coherent conversion process known as four-wave mixing Bragg scattering (FWM-BS) [11], as depicted in Fig. 1.…”