Sagnac-loop phase shifter with polarization-independent operation

TL;DR

This paper demonstrates a polarization-independent phase shifter using a Sagnac loop with electro-optic modulation and Faraday rotators, achieving high contrast and fast switching for quantum photonics.

Contribution

It introduces a novel bulk-optics, polarization-independent phase shifter integrating a transverse mode electro-optic modulator with Faraday rotators in a Sagnac loop.

Findings

Achieved 96% on/off contrast

Switching time of 1.6 ns

Polarization independence in phase shifting

Abstract

A bulk-optics, polarization-independent phase shifter for photonic quantum information applications is demonstrated. A transverse mode electro-optic modulator using lithium niobate is placed in a Sagnac-like loop containing Faraday rotators. This direction-dependent polarization rotation in the loop is combined with a Mach-Zehnder interferometer to form an optical switch with an on/off contrast of 96% and a switching time of 1.6 ns.