Measurement of the ‘single-photon’ velocity and classical group velocity in standard optical fibre
| Autor: | John Carroll, R M Thompson, J. D. Ingham, Ian H. White |
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| Rok vydání: | 2007 |
| Předmět: | |
| Zdroj: | Measurement Science and Technology. 18:1538-1546 |
| ISSN: | 1361-6501 0957-0233 |
| DOI: | 10.1088/0957-0233/18/5/045 |
| Popis: | When engineering secure optical communication networks, it may be important to know if the photon velocity may be altered in a dispersive fibre by selecting photonic states with different ranges of Schr?dinger frequencies, (N + 1/2)f where f is the modal frequency. This paper reports on a comparison between the velocity of approximate single-photon states (N ? 1) and the classical optical group velocity (N 1 with a range of N). The experiments use the same source and the same novel technique with a single temporal standard to measure the time of flight of both 'single photons' and classical optical energy over standard optical fibre. Within the experimental accuracy (approximately ?0.2 ns in 30?000 ns, or 6.3 km of fibre) there is no evidence for changes of velocity as the composition of the number states varies. This suggests that photons travel in a dispersive fibre with a velocity that is independent of the Schr?dinger frequencies. It is believed that this is the first such test on kilometre lengths of standard fibre. |
| Databáze: | OpenAIRE |
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