CONDENSATION PRODUCTS OF SILICIC ACID DERIVATIVES AND OPTICAL WAVEGUIDE DEVICES USING THE SAME

The present invention relates to condensation products of silicic acid derivatives usable especially in optical waveguides and particularly to a condensation product obtained by condensing a silane diol compound (A) of the general formula (1): R12Si(OR2)2 (1) wherein R1 represents a group having at least one aromatic group and having 6 to 20 carbon atoms, and R2 represents hydrogen (H which may also be a heavy hydrogen D), with a modified silane compound (B) of the general formula (2): R3Si(OR4)3 (2) wherein R3 represents an organic group having at least one C-C double bond; and R4 represents a group of CnH2n+1 (n=a number of 1 or 2), in the molar ratio 1.1 to 1.4:1 [(A):(B)], and to a process for producing the same condensation product, as well as to an optical waveguide device fabricated using the same condensation product.