| Autor: |
Nakamura, H., Nishikawa, S., Kohmoto, S., Kanamoto, K., Asakawa, K. |
| Předmět: |
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| Zdroj: |
Journal of Applied Physics; 7/15/2003, Vol. 94 Issue 2, p1184, 6p, 1 Black and White Photograph, 1 Chart, 4 Graphs |
| Abstrakt: |
The optical nonlinear properties of self-assembled InAs/GaAs quantum dots (QDs) were experimentally verified by means of transient absorption measurements. A saturation pulse energy P[SUBs] of 13 fJ/μm[SUP2] and an absorption recovery time &tou;[SUBr] of 55 ps were obtained from transmission bleaching and pump/probe measurements for a waveguide sample with ten-layer-stacked QDs. An absorption saturation intensity I[SUBs] of 2.5×10[SUP4]W/cm[SUP2], calculated from P[SUBs] and τ[SUBr], was found. The saturation pulse energy is up to an order of magnitude smaller than, or at least comparable with, the reported values for excitons in quantum wells of III-V compound semiconductors. The dipole length, as calculated from the absorption cross section, is of the same order as the lattice constant of the InAs QDs. The results are expected to experimentally verify that QDs show a delta-function-like density of states. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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