Design and manufacturing of band-rejection filters based on long period gratings for applications in next generation access networks

An engineering tool for designing LPG-based filters is reported. Band-rejection filters for telecom applications have been designed and manufactured and an automated mass production technology has been developed. The technology utilizes single-shot LPG writing with a double CO 2 laser beam. The paper discusses also the critical process parameters controlled to shape the spectral characteristics of manufactured filters.