Abstract: A high isolation optical splitter for the field of optical communications may include an integrated structure of an input fiber, a first output fiber, an input splitting/combining device, a first output splitting/combining device, an input rotation device, a first output rotation device, a first lens, an isolator core, a second lens, a second output rotation device, a second output splitting/combining device, and a second output fiber. By adopting the integrated structure, this disclosed splitter integrates functions of an optical isolator and an optical splitter, which both can input an optical signal into one input fiber and can distribute to two output optical fibers for output. The disclosed splitter can isolate light in opposite directions and can reduce damage to a light source at an input end.