Eur. Phys. J. D (2013) 67: 202
https://doi.org/10.1140/epjd/e2013-40102-x

Regular Article

A polarization maintaining scheme for 1.5 μm polarization entangled photon pair generation in optical fibers

Tsinghua National Laboratory for Information Science and Technology, Department of Electronic Engineering, Tsinghua University, Beijing 100084, P.R. China

^a e-mail: betterchou@gmail.com
^b e-mail: zwei@tsinghua.edu.cn

Received: 27 February 2013
Received in final form: 23 April 2013
Published online: 26 September 2013

Abstract

In this paper, the generation of polarization entangled photon pairs at 1.5 μm is experimentally demonstrated utilizing a polarization maintaining all-fiber loop, consisting of a piece of commercial polarization maintaining fiber and a polarization beam splitter/combiner with polarization maintaining fiber pigtails. The polarization entangled two photon state of 1/√2(|H_s⟩|H_i⟩ + e^iϕ|V_s⟩|V_i⟩) can be generated while the relative phase ϕ can be adjusted by manipulating the polarization state of the pump light. A quantum state tomography measurement is performed to analyze the entanglement characteristic of the generated quantum state. In the experiment, the polarization entangled Bell state  |Φ⁺⟩  is generated with an entanglement fidelity of 0.97 ± 0.03 and a purity of 0.94 ± 0.03 demonstrating that the proposed scheme can realize polarization entangled photon pair generation with polarization maintaining property which is desired in applications of quantum communication and quantum information.