Berlin 2014 – wissenschaftliches Programm

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Q: Fachverband Quantenoptik und Photonik

Q 38: Quantum information: Photons and nonclassical light I

Q 38.4: Vortrag

Donnerstag, 20. März 2014, 11:15–11:30, UDL HS3038

A Mode-filter-free Source of Narrow-band Photon-pairs — •Amir Moqanaki and Philip Walther — University of Vienna, Vienna, Austria

Narrow-band (few MHz band-width) single photons are an essential tool for a variety of quantum information studies, atomic quantum memories, quantum networks, and studying atom-light interactions.

Spontaneous Parametric Down-Conversion (SPDC) has proven to be a robust, relatively easy, bright, probabilistic source of photon-pairs. But the typical phase-matching band-width is broad (about 100 GHz or more) and filtering such leads to very poor brightness.

On the other hand, SPDC inside a high finesse cavity can enhance the narrow-band emission by a factor of finesse squared and drastically improve the brightness. But for single longitudinal mode operation of the enhancing cavity, additional external filters (either atomic line, or etalons) are necessary. This mode filtering comes at the cost of losing photon counts and adding complexity to the setup.

In this talk, a novel mode-filter-free, frequency degenerate, type-II phase-matched, SPDC based source of narrow-band photon-pairs at 780nm is introduced. An intra-cavity Pockels cell tunes the signal and idler photons free spectral ranges such that they satisfy the doubly resonant condition and render the cavity single mode. This technique improves the brightness and packs a compact, robust setup.