A variable partially-polarizing beam splitter

TL;DR

This paper introduces designs for variable partially-polarizing beam splitters that enable independent control of polarization splitting ratios, with an experimental demonstration of a stable, easily assembled implementation suitable for quantum optics applications.

Contribution

The paper presents novel designs for variable polarizing beam splitters with independent control, including a practical, stable implementation using common optical components.

Findings

Demonstrated a displaced Sagnac interferometer as a stable beam splitter.

Achieved independent control of horizontal and vertical polarization ratios.

Used standard optical components, simplifying experimental setup.

Abstract

We present designs for variably polarizing beam splitters. These are beam splitters allowing the complete and independent control of the horizontal and vertical polarization splitting ratios. They have quantum optics and quantum information applications, such as quantum logic gates for quantum computing and non-local measurements for quantum state estimation. At the heart of each design is an interferometer. We experimentally demonstrate one particular implementation, a displaced Sagnac interferometer configuration, that provides an inherent instability to air currents and vibrations. Furthermore, this design does not require any custom-made optics but only common components which can be easily found in an optics laboratory.