Abstract
An attractive and challenging approach to the construction of robust, thin film materials with large second-order optical nonlinearities is the covalent self-assembly of aligned arrays of high-β molecular chromophores into multilayer superlattices. In this paper, we describe the dispersion of second harmonic generation (SHG) in a self-assembled (SA) monolayer containing a stilbazolium chromophore. The frequency-dependent measurements were performed on 25 angstrom thick monolayers on glass using a tunable (0.4-2 μm) light source based on optical parametric amplification (OPA). The SHG spectrum contains a clear two-photon resonance at ℏω = 1.3eV. The maximum in the second-order susceptibility coincides with a low energy chromophore-centered charge-transfer excitation at 480 nm. The experimental SHG dispersion values compare favorably with theoretical results computed using a sum-over-states (SOS) formalism. However, the measured values exhibit a somewhat broader band response than the theoretical curve, and the origin of this behavior is discussed.
| Original language | English |
|---|---|
| Pages (from-to) | 119-125 |
| Number of pages | 7 |
| Journal | Materials Research Society Symposium - Proceedings |
| Volume | 351 |
| DOIs | |
| State | Published - 1994 |
| Externally published | Yes |
| Event | Proceedings of the 1994 MRS Symposium - San Francisco, CA, USA Duration: 4 Apr 1994 → 8 Apr 1994 |