Method for optical waveguide fabrication using polysiloxane, epoxy, photo acid generator, and hydrosilation catalyst

A method for producing an optical waveguide;

• said method comprising steps of:
• (a) depositing on a substrate a first composition comprising:
• (i) a first polysiloxane comprising epoxy groups and alkenyl groups, and (ii) at least one first compound comprising an epoxy group, having molecular weight no greater than 1000 and a refractive index of at least 1.47;
• (iii) at least one photo acid generator (iv) at least one hydrosilation catalyst
• (b) curing the first composition by exposure to ultraviolet light through a mask to produce a patterned core layer comprising a cured portion of the first composition and an uncured portion of the first composition;
• (c) removing at least a part of the uncured portion of the first composition to produce a final patterned core layer;
• (d) depositing on the final patterned core layer a second composition comprising:
• (i) a second polysiloxane comprising epoxy groups, (ii) at least one second compound comprising an epoxy group and a silicon-hydrogen bond, having molecular weight no greater than 1000 and a refractive index no greater than 1.45;
• and (iii) at least one photo acid generator, to produce a composite;
• (e) heating the composite at a temperature from 20 to 150° C. for 0.1 to 120 minutes;
• (f) curing by exposure to ultraviolet light;
• and
• (g) heating at a temperature from 60 to 210° C. for 0.1 to 10 hours.