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

In this article, 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 for at least 10 hours of continuous operation, achieving coincidence-to-accidental ratios of more than 2000 consistently over this time period.