PREPARATION AND WAVE-GUIDE PROPERTIES OF POLYGLUTAMATE LANGMUIR-BLODGETT-FILMS

An efficient method for the synthesis of poly[(gamma-methyl-L-glutamate)-co-(gamma-n-octadecyl-L-glutamate)] is presented. Multilayer assemblies were prepared by the Langmuir-Blodgett (LB) method. Waveguide experiments were used to determine the optical properties of the LB film including the dispersion and the anisotropy of the refractive index. Extraordinary Abbe numbers larger than 100 are achieved. An anisotropy parallel and perpendicular to the dipping direction of the LB film of DELTA-n = 0.01 is found. The waveguide losses were measured by monitoring the stray light of the film with a diode array. An attenuation coefficient in the order of 2 dB cm-1 at the wavelength 530.9 nm was measured, with a LB film only 542.5 nm thick. Calculations of the field intensity distribution show that this corresponds to an intrinsic attenuation of approximately 5-7 dB cm-1 for an LB film of this polyglutamate.