Turn-key diode-pumped all-fiber broadband polarization-entangled photon source

Changjia Chen,Arash Riazi,Mili Ng,Alexey V Gladyshev,Eric Y Zhu,Peter G Kazansky,Li Qian

doi:10.1364/osac.1.000981

Abstract

In this letter, we report a compact, low-power laser diode-pumped, all-fiber polarization-entangled photon pair source based on periodically-poled silica fiber technology. The all-fiber source offers room-temperature, alignment-free, turn-key operation, with low power consumption, and is packaged into a fanless, portable enclosure. It features a broad biphoton spectrum of more than 100nm with a concurrence that is greater than 0.96 for polarization entanglement. The source is stable over at least 10 hours of continuous operation, achieving coincidence-to-accidental ratios of more than 2000 consistently over this time period.

Highlights

Practical applications of quantum entanglement-based photonic technologies such as quantum interferometry [1] and long-distance quantum key distribution [2, 3] often require robust and high performance entangled photon source
Though polarization-entangled photon sources based on dispersion-shifted fibers [14, 15], polarization-maintaining fibers [16, 17], and photonic crystal fibers [18] have been investigated in the past decades, due to the lack of second-order nonlinearity and difficulty in phase-matching, they either do not operate in the telecom wavelength region, or require cryogenic cooling to reduce Raman noise
In contrast to the biphoton sources based on the third-order nonlinearity of optical fiber, periodically-poled silica fiber (PPSF) [19] uses the induced second-order nonlinearity in poled fiber to generate polarization-entangled photon pairs [20] based on type-II spontaneous parametric down conversion (SPDC)

Summary

Introduction

Practical applications of quantum entanglement-based photonic technologies such as quantum interferometry [1] and long-distance quantum key distribution [2, 3] often require robust and high performance entangled photon source. Temporal compensation or erasure of distinguishability through interferometry is always required in these types of fiber-based sources to achieve high-quality entanglement, which greatly increases the complexity of the construction, and requires the use of free-space optics in most cases.

Results

Conclusion