Abstract
Interest in the lowest even-parity two-photon states in linear-chain π-conjugated polymers has been largely limited to their energies relative to the lowest odd-parity one-photon state. We show that the intensities of the two-photon absorptions to even-parity states that occur below the lowest one-photon states should be tiny in the infinite chain, because of cancellations. This has important implications for the interpretation of third-harmonic generation spectra of polydiacetylenes. A resonance seen in third-harmonic generation of polydiacetylenes that has commonly been assigned as a two-photon resonance is interpreted here as a three-photon resonance.
| Original language | English |
|---|---|
| Pages (from-to) | 10102-10112 |
| Number of pages | 11 |
| Journal | Physical Review B |
| Volume | 49 |
| Issue number | 15 |
| DOIs | |
| Publication status | Published - 1994 Jan 1 |
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Condensed Matter Physics