1.
Opt Express
; 27(4): 4292-4303, 2019 Feb 18.
Article
in English
| MEDLINE
| ID: mdl-30876046
ABSTRACT
We report on the detailed investigation of the core to cladding mode coupling in femtosecond-written long period fiber gratings (LPFG). It is shown that the excitation of higher-order cladding modes with strong selectivity and high precision is possible. The coupling behavior of several gratings, as well as its dependence on the modified core cross-section, is determined theoretically and confirmed experimentally by its spectral response. The presented tool paves the way for a completely new class of tailored LPFGs for different fiber integrated devices.