Wavelength flattened directional couplers for mirrorsymmetric interferometers

TL;DR

This paper develops a rigorous design criterion for wavelength-insensitive, mirror-symmetric interferometers in guided optics, enabling broadband operation over more than 70 nm for wavelength multiplexing applications.

Contribution

It introduces a new analytical and geometric criterion for designing wavelength-flattened, mirror-symmetric interferometers in guided optics.

Findings

Achieved interferometer bandwidth wider than 70 nm.

Provided a general design criterion for wavelength insensitivity.

Validated the criterion with a practical interferometer example.

Abstract

In the context of guided optics, we derive, analytically and geometrically, a rigorous general criterion to design wavelength insensitive interferometers with mirror symmetry, which are needed for wavelength multiplexing/demultiplexing. The criterion is applied to a practical case, resulting in an interferometer that works on a band wider than 70 nm.