BI-DIRECTIONAL PUMP LIGHT FIBER FOR ENERGY TRANSFER TO A CLADDING PUMPED FIBER

摘要

An X-junction side coupler is formed by the attachment of a clad stripped special pump fiber to a section of the cladding pumped fiber with its outer cladding removed. The special formulated core of the pump fiber has a lower refractive index than the inner cladding of the cladding pumped fiber, and the resulting composite structure forms an anti-guide for the pump light. Due to the differential refractive index at the interface of the two guides leaky modes are generated to strip away the pump light efficiently and irreversibly from the pump guide to the cladding pumped fiber. An appropriate coupling length will ensure pump light injected in one end will not interfere with the source at the opposite end thus allowing bi-directional pumping in each coupling site. This new device invention facilitates the implementation of distributed pump architecture for cladding pumped fiber devices enabling very high power scaling with good thermal management control.