The transmission spectrum of a long-period fiber grating was analyzed theoretically for an optical fiber whose material dispersion in the cladding region was modified by doping a transition metal, Cr3+. By doping Cr3+ ions into the cladding, we were able to change the effective indices of cladding modes and subsequently the phase matching conditions for coupling with the core mode in a long-period fiber grating. Enhancement of the free spectral range in the long-period fiber grating over 400 nm were rigorously predicted in the proposed fiber structures, which could be applicable in novel filters for a wide band optical communication systems.
Bibliographical noteFunding Information:
This research is partly funded by the KOSEF through UFON ERC program in KJIST, BK21 program supported by MOE and CHOAN ITRC program supported by MIC.
All Science Journal Classification (ASJC) codes
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Physical and Theoretical Chemistry
- Electrical and Electronic Engineering