Robust Multiwavelength All-Fiber Source of Polarization-Entangled Photons With Built-In Analyzer Alignment Signal

We describe an all-fiber source of polarization-entangled photons, which is designed to be simple to manufacture and structurally robust. The source includes an alignment signal that allows for straightforward alignment of the measurement axes of the subsequent polarization analyzers. High-quality entangled light is generated and measured at multiple wavelength channels within the C-band.