| Autor: |
Euser, Tijmen G., Wei, Hong, Kalkman, Jeroen, Jun, Yoonho, Polman, Albert, Norris, David J., Vos, Willem L. |
| Rok vydání: |
2007 |
| Předmět: |
|
| Zdroj: |
J. Appl. Phys. 102, 053111 (2007) (6 pages) |
| Druh dokumentu: |
Working Paper |
| DOI: |
10.1063/1.2777134 |
| Popis: |
We present ultrafast optical switching experiments on 3D photonic band gap crystals. Switching the Si inverse opal is achieved by optically exciting free carriers by a two-photon process. We probe reflectivity in the frequency range of second order Bragg diffraction where the photonic band gap is predicted. We find good experimental switching conditions for free-carrier plasma frequencies between 0.3 and 0.7 times the optical frequency: we thus observe a large frequency shift of up to D omega/omega= 1.5% of all spectral features including the peak that corresponds to the photonic band gap. We deduce a corresponding large refractive index change of Dn'_Si/n'_Si= 2.0% and an induced absorption length that is longer than the sample thickness. We observe a fast decay time of 21 ps, which implies that switching could potentially be repeated at GHz rates. Such a high switching rate is relevant to future switching and modulation applications. |
| Databáze: |
arXiv |
| Externí odkaz: |
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