Berlin 2001 – wissenschaftliches Programm
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Q: Quantenoptik
Q 22: Poster: Quantum Effects
Q 22.6: Poster
Donnerstag, 5. April 2001, 12:30–15:00, AT2
Stable Single Photon Sources — •Christoph Braig1, Patrick Zarda2, Christian Kurtsiefer1, and Harald Weinfurter1,2 — 1Sektion Physik der LMU München, Schellingstr. 4/III, 80799 München — 2Max-Planck-Institut für Quantenoptik, Hans-Kopfermann-Str. 1, 85748 Garching
For the security of quantum cryptography but also for fundamental experiments in quantum mechanics, single photon sources are indispensable. Recently investigated single photon source systems like quantum dots or dye molecules usually need low temperatures or suffer from photo bleaching.
Our source utilizes the fluorescence from a single Nitrogen-Vacancy (NV) center in type Ib diamond. A single NV-center is excited at room temperature in a confocal microscope set-up with a frequency-doubled Nd:YVO4 laser at 532 nm. We analyze the fluorescence light either with a grating spectrometer to clearly identify the center or with a Hanbury-Brown–Twiss setup to demonstrate the non-classical photon statistics. The fluorescence of NV-centers clearly shows antibunching without any evidence of photo bleaching.
Recent experiments concentrate on testing diamond nanocrystals and CVD layers of diamond. These systems should allow for a higher collection efficiency, and possibly contain other fluorescing defects with spectral characteristics well suited for practical applications.