Abstract
The nonlinear transmission and the excited-state absorption spectra of three fluorene derivatives exhibiting large two-photon absorptivity were measured by the third harmonic of a picosecond Nd:YAG laser. We analyzed their capability for exhibiting stimulated emission in polar solvents and found that asymmetrical fluorene compounds with a diphenylamino substituent exhibited large Stokes shifts (∼8000 cm-1), high quantum yields (∼0.9-1.0), and no optical gain over their entire fluorescence spectral region. In contrast, a symmetrical fluorene derivative with vinylphenylbenzothiazole substituents in positions 2 and 7 underwent lasing under one-photon excitation by use of picosecond pulsed irradiation.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 6339-6343 |
| Number of pages | 5 |
| Journal | Applied Optics |
| Volume | 43 |
| Issue number | 34 |
| DOIs | |
| State | Published - Dec 1 2004 |
| Externally published | Yes |
All Science Journal Classification (ASJC) codes
- Atomic and Molecular Physics, and Optics
- Engineering (miscellaneous)
- Electrical and Electronic Engineering