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.
Cite
@article{arxiv.0804.2135,
title = {Sagnac-loop phase shifter with polarization-independent operation},
author = {Tien Tjuen Ng and Darwin Gosal and Antia Lamas-Linares and Christian Kurtsiefer},
journal= {arXiv preprint arXiv:0804.2135},
year = {2011}
}