The femtosecond bleaching dynamics of polydiacetylene. Transient room-temperature spectral hole-burning features
✍ Scribed by Jean-Michel Nunzi; Charles Hirlimann; Jean-François Morhange
- Publisher
- Elsevier Science
- Year
- 1994
- Tongue
- English
- Weight
- 538 KB
- Volume
- 221
- Category
- Article
- ISSN
- 0009-2614
No coin nor oath required. For personal study only.
✦ Synopsis
The femtosecond exciton bleaching dynamics in a thin film of polycrystalline polydiacetylene is studied using 2 eV resonant pumping under saturation conditions. A transient hole is burnt in the inhomogeneous spectrum, 20 meV below the pump energy at room temperature. Within the 100 fs excitation step, the hole is associated with two symmetric phonon replica 35 meV apart. These replica are assigned to a lowenergy Raman mode strongly coupled to the exciton and characterized by large Franck-Condon factors. The differential decay of the two side holes reveals an exciton relaxation rate which is twice as fast as the ground staterecoveryrateofl.lx10'2s-'.