ENHANCED 2ND-HARMONIC RESPONSE AND STABILITY OF CORONA-POLED GUEST-HOST POLYCARBONATE THIN-FILMS

Second-harmonic generation and spectroscopic absorption measurements w ere made to study the non-linear optical and stability properties of g uest/host polycarbonate th in films in which the guest chromophores we re oriented by corona poling. Optimum poling conditions were achieved at temperatures less than the glass-rubber transition temperatures. St abilized order parameters as high as 0.23 and retention of orientation al order as high as 86% were found. Stable, resonance-enhanced, values of the non-linear optical coefficient d(33), for the fundamental of 1 .064 mu m, were as high as 31 mu m V-1. This value is over four times that predicted by a simple thermodynamic model for isotropic materials . Hydrogen bonding: between the guest and polycarbonate is proposed to account for the high d(33) coefficients and long-term stability of th e films.