Thermo-optical coefficient determination of index liquids used for optimization of optical integrated components

The optimization procedure for designing silica integrated components (spec ially in the telecommunication infrared spectrum, around wavelength 1550 nm ) uses specific index liquids as a core top layer. These liquids consist of transparent silicone oils which present a very low vapor pressure. In this paper we present an accurate method to measure the thermo-optical coeffici ent of these liquids. We determine that, for liquid based silicone, this co efficient is -4.5 x 10(-4) K-1. By the way, this technique also enable us t o know the behavior of integrated directional coupler as thermo-optical swi tch. These experiments are useful to design such kind of integrated compone nts. (C) 2001 Elsevier Science B.V. All rights reserved.