Patent ID: 7035506

Claim:
An optical module, comprising: at least one optical fiber having an end surface; a gradient index rod lens, wherein the rod lens is placed at a position separated form the end surface of the at least one optical fiber by a space; and an optical element that is separated from the rod lens, wherein outgoing light from the at least one optical fiber is inputted to the optical element via the rod lens, and light reflected by the optical element is occupied to the at least one optical fiber via the rod lens; and an optical circulator connected to the incoming optical fiber, the optical circulator having a first terminal, a second terminal, and a third terminal, wherein at least one optical fiber is a single incoming optical fiber that is located at an incoming side of the rod lens and is coaxial with the rod lens, wherein a distance between the rod lens and the optical element is longer than about 0.4 mm and a lens length is in a range between about 0.21 pitch and 0.1 pitch, and the rod lens has end surfaces perpendicular to an optical axis.