Abstract
We report on the observation of ultrafast (<1 ps) recovery of all-optical modulation based on below band gap, optically induced excess absorption using pump pulse energies of less than 4 pJ. At higher pump pulse energies, the hot carriers produced by two-photon absorption significantly reduce the recovery rate. The increase in absorption recovery times at the higher densities of hot carriers is consistent with a contribution to the nonlinear absorption change from hot electron assisted absorption. The measured hot electron assisted absorption cross section of 2×10-20 m2 is in good agreement with the theoretical value.
Original language | English |
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Pages (from-to) | 1451-1453 |
Number of pages | 3 |
Journal | Applied Physics Letters |
Volume | 62 |
Issue number | 13 |
DOIs | |
Publication status | Published - 1 Dec 1993 |
ASJC Scopus subject areas
- Physics and Astronomy (miscellaneous)