Patent ID: 7978418

Claim:
An optical device comprising: a first capillary tube assembly including a first capillary tube into which an optical fiber is inserted and fixed, and a first retaining member for retaining the first capillary tube; a second capillary tube assembly including a second capillary tube into which an optical fiber is inserted and fixed, and a second retaining member for retaining the second capillary tube; and a lens assembly including: a first lens that faces a leading end of the first capillary tube with a gap between the first lens and the first capillary tube assembly; a second lens that faces a leading end of the second capillary tube with a gap between the second lens and the second capillary tube assembly; an optical functional component interposed between the first lens and the second lens; a lens holder having a through hole; and an accommodation member for accommodating the first lens, second lens, optical functional component and the lens holder, wherein at least one of the first lens and the second lens is a spherical lens having a flat surface portion, the lens holder is adjacent to and fixed to the at least one of the first lens and the second lens such that a spherical surface portion of the at least one of the first lens and the second lens abuts an edge portion of one end side of the through hole of the lens holder, and the first retaining member of the first capillary tube assembly is fixed to one end surface of the accommodation member, and the second retaining member of the second capillary tube assembly is fixed to another end surface of the accommodation member.