Authors:
Nuno A. Silva
and
Armando N. Pinto
Affiliation:
University of Aveiro and Instituto de Telecomunicações, Portugal
Keyword(s):
Quantum Correlated Photon-pairs, Raman Scattering, Spontaneous Four-wave Mixing, Waveguide Absorption.
Related
Ontology
Subjects/Areas/Topics:
Fiber Optics
;
Lasers
;
Mobile Software and Services
;
Nonlinear Optics
;
Optics
;
Photonics
;
Photonics, Optics and Laser Technology
;
Quantum Information and Measurement
;
Telecommunications
;
Wireless Information Networks and Systems
Abstract:
We investigate the impact of waveguide loss on the generation rate of quantum correlated photon-pairs through
four-wave mixing in a chalcogenide glass fiber. The obtained results are valid even when the photon-pairs are
generated in a medium with non-negligible loss, αL>> 1. The impact of the loss is quantified through the
analysis of the true, total and accidental counting rates at waveguide output. We use the coincidence-to-
accidental ratio (CAR) as a figure of merit of the photon-pair source. Results indicate that, the CAR parameter
tends to decrease with the increase of the waveguide length, until L < 1/α. However, a continuous increase of
the waveguide length tends to lead to an increase on the CAR value. In that non-negligible loss regime, αL>>1,
we are able to observe a significant decrease on the value of all coincidence counting rates. Nevertheless, that
decrease is even more pronounced on the accidental counting rate. Moreover, for waveguide length L = 10/α
we are able to obtain a CAR of the order of 70, which is higher than the CAR value for the specific case of
α = 0 with L = 2 cm, i.e. CAR=42. This indicates that the waveguide loss can improve the degree of quantum
correlation between the photon-pairs.
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