Degenerate Distributed Feedback Photonic Structure with Double Grating Exhibiting Degenerate Band Edge

TL;DR

This paper introduces a novel photonic structure with a degenerate band edge achieved through coupled gratings, promising advancements in degenerate distributed feedback lasers.

Contribution

It proposes a new degenerate Bragg condition and a structure with coupled gratings to realize a degenerate band edge in photonic devices.

Findings

Verification of DBE via eigenmode and scattering parameter calculations

Design of a structure suitable for degenerate distributed feedback lasers

Potential for enhanced laser performance at the DBE

Abstract

We propose a degenerate version of the Bragg condition, associated to a degenerate band edge (DBE). A standard Bragg condition can be implemented using a periodic grating that operates at the regular band edge. The structure we propose to realize a DBE is made of two stacked identical gratings that form two coupled periodic waveguides with broken mirror symmetry. The occurrence of the DBE is verified by using both an eigenmode solver and the calculations of scattering parameters, using full-wave simulations. The proposed structure is a good candidate to conceive a degenerate distributed feedback lasers operating at the DBE.