Note: An ultranarrow bandpass filter system for single-photon experiments in quantum optics.
We describe a combined ultranarrow bandpass filtering setup for single-photon experiments in quantum optics. The filter is particularly suitable for single-photon electromagnetically induced transparency (EIT) experiments, but can also be used in several similar applications. A multipass planar Fabry-Perot etalon together with polarization filters and spatial filtering allows 114 dB pump beam suppression, while the signal beam is attenuated by just 4 dB, although both wavelengths are only separated by 0.025 nm (9.2 GHz). The multipass etalon alone accounts for 46 dB suppression while it has a peak transmission of 65%. We demonstrate EIT experiments in Cs vapor at room temperature with probe power in the femtowatt regime using this filter.
Höckel
David
D
Nano Optics, Institute of Physics, Humboldt-Universität zu Berlin, Hausvogteiplatz 5-7, 10117 Berlin, Germany. david.hoeckel@physik.hu-berlin.de
Martin
Eugen
E
Benson
Oliver
O