Guest-host polymeric systems as non-linear optical materials

The use of a constant current corona triode in probing the orientation of guest-host nonlinear optical polymers is reported. The use of the constant current arrangement provides information on the surface voltage of the thin film samples during the poling cycle. Dopant nonlinear optical molecules in either poly(methyl methacrylate) (PMMA) and polycarbonates show marked differences in the alignment behaviour as monitored by surface voltage changes. In PMMA, the alignment appears to comprise a simple process attributable only to the dipolar dopant. In the polycarbonates, themselves polar electrets, the alignment exhibits more complex behaviour. Simple dipolar dopant alignment is completed before a longer period of chain dipole alignment occurs. These differences may be important in explaining our previous observations of unusual alignment stability in polycarbonate-based guest-host films.