| abstract |
The present invention relates to a method for producing an optical waveguide by: (a) depositing a first composition comprising: (i) a polysiloxane, comprising epoxy and alkenyl groups, having a lower refractive index or equal to 1.50, (ii) a compound comprising at least one epoxy group and having a refractive index less than or equal to 1.49, and (iii) a polysiloxane having a refractive index of at least 1.50; (iv) a photoacid generator; (v) a hydrosilylation catalyst, (vi) a hydrosilylation inhibitor; (b) curing by exposure to ultraviolet light; (c) removing the uncured portion to produce a patterned core layer; (d) after a period of 20 to 300 hours, depositing a second composition comprising: (i) a polysiloxane comprising epoxy groups having a refractive index less than or equal to 1.49, and (ii) a compound comprising at least minus two epoxy groups having a refractive index less than or equal to 1.49 and an alcohol having a refractive index less than or equal to 1.45, (iii) at least one photoacid generator. |