Large mode area fibers by using conversion to higher order modes

摘要

The specification describes an optical fiber device wherein a lower order mode (LOM) is converted to an higher order mode (HOM) prior to entering the gain section. The gain section is a few mode fiber that supports the HOM. The output from the gain section, i.e. the HOM, may be utilized as is, or converted back to the LOM. With suitable design of the few mode fiber in the gain section of the device, the effective area, Aeff, may be greater than 1600 µm 2 . The large mode separation in the gain section reduces mode coupling, allowing greater design freedom and reducing the bend sensitivity of the optical fiber. The innder cladding and trench regions govern the properties of the higher order mode (HOM).