TWO-PHOTON ABSORPTION INDUCED EFFECTS IN CRYSTALLINE POLYSILANE FILMS

Abstract

The new class of polysilane polymers has recently attracted interest as a medium for nonlinear optical interactions. These materials consist of a long (>1000 atoms) σ-bonded silicon backbone with two organic substituent groups attached to each Si atom. As nonlinear materials, these have several advantages over their π-bonded carbon analogs, the polydiacetylenes. First, polysilanes have been extensively investigated as possible photoresists,1 so thin (≤4 μm) films of excellent optical quality can be easily prepared using conventional photoresist technology. Second, the σ-σ* absorption edge is typically in the ultraviolet, so the material is transparent at all visible wavelengths. Finally, this absorption band edge can be shifted by changing the molecular weight, conformation of the Si backbone, or the substituent groups, making resonant enhancement of nonlinear effects at particular wavelengths possible. © 1988 Optical Society of America