Production of optical notch filters with fine parameter control using regenerated fiber Bragg gratings

Abstract

A new method to create a controlled notch filter for attenuation of signals based on regenerated fiber Bragg gratings is experimentally demonstrated. A fine adjustment of the notch depth is achieved by controlling the time of regeneration phenomenon in strongly saturated Bragg gratings written in standard ITU G.652 single-mode fiber. This method can used to produce tailored notch filters for several photonic applications, such as optical RF filtering, subcarrier processing or radio over fiber systems.

Thin film notch filters as platforms for biological image processing

“…Here we demonstrate the use of a commercially available thin film spectral notch filter applied to phase contrast imaging of transparent samples. Notch filters are band-stop filters commonly employed in various types of spectroscopy to remove temporal frequencies over a specific range 40 , 41 . The angular dispersion of the filter’s rejection band is shown to produce a high-pass spatial frequency filter at the operating wavelength.…”