Dual-band Photonic Filters with Wide Tunable Range Using Chirped Sampled Gratings

TL;DR

This paper presents a silicon-based dual-band photonic filter with wide tunability, utilizing chirped sampled gratings and thermo-optic effects to achieve independently adjustable passbands over a broad frequency range.

Contribution

The work introduces a novel dual-band filter design with wide tunable range using reconstructed chirped gratings and integrated micro-heaters for independent control.

Findings

Dual passbands can be independently tuned.

Frequency interval adjustable from 37.2 GHz to 186.1 GHz.

Wide tuning range achieved via thermo-optic effect.

Abstract

We have developed a photonic filter featuring dual independently tunable passbands. Employing the reconstruction equivalent-chirp technique, we designed linearly chirped sampled Bragg gratings with two equivalent phase shifts positioned at 1/3 and 2/3 of the cavity, thus introducing two passbands in the +1st channel. Leveraging the significant thermo-optic effect of silicon, dual-band tuning is achieved via micro-heaters integrated on the chip surface. By tuning the injection currents ranging from 0 to 35 mA into the micro-heaters, the filter exhibits a wide range of dual-wavelength filtering performance, with the frequency interval between the two passbands adjustable from 37.2 GHz to 186.1 GHz.