Applied Physics Letters

A monolithic polarization-independent frequency-filter system for filtering of photon pairs

Andreas Ahlrichs, Christoph Berkemeier, Benjamin Sprenger, Oliver J. Benson

Published Dec 9, 2013• 15 citations

Abstract

We set up a long-term stable filtering system that consists of cascaded monolithic Fabry-Pérot filters to enhance the suppression and free spectral range. An effective free spectral range of hundreds of GHz allows the system to be used as a high resolution monochromator, with a linewidth of 192 MHz. As an important application a single mode is filtered from photon pairs generated by a parametric down-conversion source, and their indistinguishability is proven by measuring the Hong-Ou-Mandel effect with a visibility of 96%. We report that undesired birefringence, which is often encountered with monolithic cavities, can be avoided by stress-free mounting.

DOI: 10.1063/1.4846316

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