Production method for gi optical waveguide

A production method for an optical waveguide, the production method comprising:

• a first step of inserting a needle-like portion at a tip end of an ejection unit into uncured cladding;
• a second step of moving the needle-like portion in the uncured cladding while ejecting an uncured material from the needle-like portion to form an uncured core surrounded and covered with the uncured cladding;
• a third step of removing the needle-like portion from the uncured cladding;
• and
• a fourth step of curing the uncured cladding and the uncured core, wherein
• the uncured cladding is composed of a composition including 100 parts by mass of a reactive silicone compound (a) composed of a polycondensate of a diarylsilicic acid compound A of Formula [1] and an alkoxy silicon compound B of Formula [2], or a polycondensate of the diarylsilicic acid compound A, the alkoxy silicon compound B, and another polycondensable compound, and 1 part by mass to 200 parts by mass of a di(meth)acrylate compound (b) of Formula [3], and
• the uncured core is composed of a composition including 100 parts by mass of a reactive silicone compound (x) composed of a polycondensate of a diarylsilicic acid compound A of Formula [1] and an alkoxy silicon compound B of Formula [2], or a polycondensate of the diarylsilicic acid compound A, the alkoxy silicon compound B, and another polycondensable compound, and 1 part by mass to 100 parts by mass of an aromatic vinyl compound (y) of Formula [4]:
• (wherein Ar1 and Ar2 are independently a phenyl group optionally substituted with a C1-6 alkyl group, a naphthyl group optionally substituted with a C1-6 alkyl group, or a biphenyl group optionally substituted with a C1-6 alkyl group),
• Ar3—Si(OR′)aR23-a [2]
• (wherein Ar3 is a phenyl group having at least one group having a polymerizable double bond, a naphthyl group having at least one group having a polymerizable double bond, or a biphenyl group having at least one group having a polymerizable double bond, R1 is independently methyl group or ethyl group, R2 is methyl group, ethyl group, or vinylphenyl group, and a is 2 or 3),
• (wherein R3 and R4 are independently a hydrogen atom or methyl group, R5 is a hydrogen atom, methyl group, or ethyl group, L1 and L2 are independently a C2-6 alkylene group, and m and n are 0 or a positive integer, wherein m+n is 0 to 20),
• (wherein R6 is a hydrogen atom or methyl group, L3 is a single bond, a hydrogen atom, an oxygen atom, a C1-20 q-valent aliphatic hydrocarbon residue optionally substituted with a phenyl group, or a C1-20 q-valent aliphatic hydrocarbon residue optionally including an ether bond, Ar4 is a p+1-valent aromatic hydrocarbon residue, p is independently 1 or 2, and q is an integer of 1 to 3 (wherein q is 1 when L3 is a hydrogen atom, and q is 2 when L3 is a single bond or an oxygen atom)).