Integrated Supermode Photonics Enabled by Supersymmetric Transformation

TL;DR

This paper introduces a scalable method using supersymmetric transformation to generate and excite multiple supermodes in integrated photonics, enabling high-capacity data transmission and new light manipulation techniques.

Contribution

It develops a 2nd-order discrete supersymmetric transformation method for simultaneous supermode excitation and detection, demonstrated with low-loss multiplexing systems.

Findings

Achieved low insertion loss (< 2.48 dB) and low crosstalk (< -18 dB) over 100 nm bandwidth.

Demonstrated high-speed data transmission of 1.024 Tb/s with low bit error rate.

Validated the method with experimental realization of two- and four-supermode systems.

Abstract

We report a systematic methodology to obtain supermodes with equidistant effective index distribution and to excite arbitrary target supermodes with high precision. By employing a multi-well optical potential realized by a judiciously designed waveguide array, the supported supermodes achieve maximal spacing and an equidistant distribution in effective index. More importantly, we develop a 2nd-order discrete supersymmetric (DSUSY) transformation method that enables the excitation and detection of two supermodes at the same time and can be extended to any number of supermodes via simple cascading. Together, these findings overcome the long-standing bottlenecks in integrated supermode photonics and provide an intrinsically scalable route towards harnessing supermodes as a new degree of freedom for encoding, transmitting, and processing information. We experimentally demonstrate the feasibility and universality of this method by realizing two- and four-supermode multiplexing systems. Benefitting from the large effective index spacing between supermodes and the isospectral nature of the DSUSY transformation, the fabricated devices show low insertion losses (< 2.48 dB at 1550 nm) and intermodal crosstalk (< -18 dB at 1550 nm) for all mode channels over a 100-nm wavelength range (1500-1600 nm). The high-speed data transmission experiment performed on the four-channel system achieves an aggregate data rate of 1.024 Tb/s while maintaining considerably low bit error rates, underscoring the potential of supermode photonics for high-capacity on-chip optical communications. This work lays the foundation for integrated supermode photonics, which uses supermodes as a new degree of freedom for light manipulation and opens new avenues for supermode-based applications including but not limited to on-chip optical communications, intelligent optical computing and quantum information technologies.