The characteristics of an apodized long-period grating are studied experimentally and theoretically. It has no side-lobes and almost zero insertion loss in the pass band. Changing the dc and maximum ac index along the z direction of LPG can conveniently control wavelength and the value of peak loss. Suitable spectral profile of gain-flattening filter with low insertion loss is obtained by writing two or three consecutive apodized sub-gratings in one fiber with the different UV power level in the second exposure. The experiment results are in good agreement with the simulation results.
- Gain-flattening filter
- Long-period grating
ASJC Scopus subject areas
- Electronic, Optical and Magnetic Materials
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Electrical and Electronic Engineering