Integrated Supermode Photonics Enabled by Supersymmetric Transformation

Chao Lu; Jingchi Li; Kaile Chen; Lu Sun; Qi Lu; Yikai Su; Yuan Zhong; Yuru Li; Zhaohui Li

arxiv: 2604.18999 · v1 · submitted 2026-04-21 · ⚛️ physics.optics

Integrated Supermode Photonics Enabled by Supersymmetric Transformation

Kaile Chen , Qi Lu , Yuan Zhong , Jingchi Li , Yuru Li , Zhaohui Li , Chao Lu , Yikai Su

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Lu Sun

This is my paper

Pith reviewed 2026-05-10 02:35 UTC · model grok-4.3

classification ⚛️ physics.optics

keywords supermode photonicsdiscrete supersymmetric transformationwaveguide arraysmode-division multiplexingintegrated opticsoptical communicationseffective index spacing

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The pith

A 2nd-order discrete supersymmetric transformation on waveguide arrays creates supermodes with evenly spaced effective indices for precise multimode control.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper shows how to design a waveguide array that forms a multi-well optical potential supporting supermodes whose effective indices are both maximally spaced and equidistant. It then introduces a second-order discrete supersymmetric transformation that lets experimenters excite or detect any chosen pair of these supermodes simultaneously, with the scheme cascading to larger numbers. If correct, this removes the previous difficulty of selectively addressing supermodes in integrated devices and turns them into a practical new encoding dimension for on-chip light. A reader should care because the resulting two- and four-channel demonstrators already run at 1.024 Tb/s aggregate rate with insertion losses below 2.5 dB and crosstalk below -18 dB across 100 nm, pointing to scalable high-capacity optical links without extra hardware.

Core claim

By realizing a multi-well optical potential with a carefully designed waveguide array, the supported supermodes acquire an equidistant effective-index spectrum; the 2nd-order DSUSY transformation then supplies an isospectral partner waveguide network that permits simultaneous excitation and detection of any two supermodes while preserving that spacing. Cascading the transformation extends the method to an arbitrary number of modes. Fabricated two- and four-supermode multiplexers therefore exhibit low loss and low crosstalk over a 100-nm band, enabling an aggregate 1.024 Tb/s data transmission experiment with low bit-error rates.

What carries the argument

The 2nd-order discrete supersymmetric (DSUSY) transformation applied to a multi-well optical potential formed by a waveguide array, which produces an isospectral partner structure that selectively couples to chosen supermodes while maintaining equidistant effective indices.

If this is right

Supermode-based multiplexers can be built with insertion loss below 2.48 dB and intermodal crosstalk below -18 dB across 1500-1600 nm.
Cascading the 2nd-order DSUSY transformation scales the approach to any number of channels without redesigning the core potential.
High-speed on-chip links become feasible at aggregate rates of at least 1.024 Tb/s while preserving low bit-error rates.
Supermodes can be treated as an independent information-carrying degree of freedom alongside wavelength and polarization.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

The same waveguide-array potential could be adapted to control supermode-based quantum gates by mapping the equidistant spectrum onto a synthetic lattice.
Testing the method at higher channel counts would reveal the practical limit set by fabrication precision before crosstalk rises above acceptable levels.
The isospectral property of the DSUSY partner suggests that the same transformation could suppress unwanted nonlinear mixing between supermodes in high-power regimes.

Load-bearing premise

The fabricated waveguide array must realize the exact multi-well potential so that the supermodes keep their designed equidistant effective-index spacing and do not suffer extra modal losses or crosstalk from fabrication error.

What would settle it

Measure the effective indices of the supported supermodes in a fabricated device and check whether their differences remain constant to within the design tolerance; a statistically significant deviation would falsify the claim that the array produces the required equidistant spectrum.

read the original 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.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Desk Editor's Note private letter to a colleague

The paper gives a practical experimental route to multiplex multiple supermodes at once using a second-order discrete supersymmetric transform on a multi-well waveguide array, with loss and crosstalk numbers that look usable for Tb/s links.

read the letter

This paper shows a workable approach to multiplex supermodes using a multi-well waveguide array for equidistant indices and a second-order discrete supersymmetric transformation to excite them simultaneously. The fabricated two- and four-channel devices achieve insertion losses below 2.48 dB and crosstalk below -18 dB over 100 nm bandwidth, supporting a 1.024 Tb/s data rate with low error rates. The new element is the 2nd-order DSUSY method that allows simultaneous handling of multiple supermodes and can cascade for more. It pairs well with the potential design to keep the spectrum clean due to isospectral properties. The experiments validate this over a broad wavelength range, which is a plus for practical use. The paper does well by focusing on experimental feasibility rather than just theory. The numbers are specific and the transmission test adds credibility. Soft spots are limited. The main one is that full verification of the index spacing and any fabrication impacts isn't detailed here, though results align with expectations. Scaling beyond four modes might need more work on accumulated losses, but that's not a central flaw. This is for photonics researchers interested in advanced multiplexing for on-chip links. A reader looking for new degrees of freedom in optics would get practical value from the demo. It deserves peer review. The experimental claims are sharp enough to merit referee input.

Referee Report

0 major / 2 minor

Summary. The paper introduces a methodology for realizing supermodes with equidistant effective-index spacing in a multi-well waveguide array and develops a 2nd-order discrete supersymmetric (DSUSY) transformation that enables simultaneous excitation and detection of multiple supermodes (extendable by cascading). Experimental demonstrations of two- and four-supermode multiplexing devices are reported, achieving insertion losses below 2.48 dB and intermodal crosstalk below -18 dB at 1550 nm across a 100 nm bandwidth (1500-1600 nm), together with a four-channel high-speed transmission experiment reaching an aggregate rate of 1.024 Tb/s with low bit-error rates.

Significance. If the experimental results hold, the work supplies a scalable, intrinsically parameter-light route to supermode multiplexing that exploits the isospectral property of SUSY transformations. The reported performance metrics and the 1.024 Tb/s transmission demonstration indicate practical utility for high-capacity on-chip communications; the ability to cascade the DSUSY blocks further suggests broader applicability to optical computing and quantum information processing.

minor comments (2)

[Abstract] Abstract: the phrase 'considerably low bit error rates' is imprecise; specific BER values (or a reference to the relevant figure or table) should be stated to allow quantitative assessment of the transmission experiment.
[Abstract] Abstract: while insertion loss and crosstalk are quoted at 1550 nm, the broadband claim (1500-1600 nm) would be strengthened by indicating whether the quoted numbers represent worst-case values across the band or peak performance at the center wavelength.

Simulated Author's Rebuttal

0 responses · 0 unresolved

We sincerely thank the referee for their careful reading and positive evaluation of our work. The referee's summary accurately captures the key contributions of our paper, and we are encouraged by the recognition of its significance for supermode multiplexing in integrated photonics. Given the recommendation for minor revision and the absence of specific major comments, we are prepared to make any necessary minor adjustments to the manuscript.

Circularity Check

0 steps flagged

No significant circularity detected

full rationale

The paper introduces a 2nd-order DSUSY transformation for designing multi-well waveguide arrays to produce supermodes with equidistant effective indices, then validates the approach through device fabrication and experimental measurements of insertion loss (<2.48 dB), crosstalk (<-18 dB), and 1.024 Tb/s aggregate transmission. No load-bearing step reduces a claimed prediction or uniqueness result to a fitted parameter, self-citation chain, or definitional tautology from the same dataset. The isospectral preservation property is invoked as a standard feature of SUSY methods and is tested against external fabrication benchmarks rather than assumed by construction. The central claims therefore rest on independent experimental outcomes.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The approach assumes that supersymmetric transformations developed in quantum mechanics can be directly discretized and applied to optical waveguide arrays while preserving the required spectral properties, and that the waveguide array can be fabricated to match the ideal multi-well potential.

axioms (1)

domain assumption Discrete supersymmetry transformations can be applied to optical waveguide arrays to map supermodes while preserving isospectral properties
The paper extends SUSY concepts from continuous quantum mechanics to discrete photonic systems without providing a self-contained derivation of the discrete version.

pith-pipeline@v0.9.0 · 5636 in / 1434 out tokens · 40707 ms · 2026-05-10T02:35:36.032142+00:00 · methodology

discussion (0)

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Works this paper leans on

1 extracted references · 1 canonical work pages

[1]

Integrated Supermode Photonics Enabled by Supersymmetric Transformation Kaile Chen1, Qi Lu1, Yuan Zhong1, Jingchi Li1, Yuru Li2, Zhaohui Li2, 3, Chao Lu4, Yikai Su1*, and Lu Sun1* 1State Key Lab of Photonics and Communications, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China 2School of Microelectronics Science a...

work page 2013

[1] [1]

Integrated Supermode Photonics Enabled by Supersymmetric Transformation Kaile Chen1, Qi Lu1, Yuan Zhong1, Jingchi Li1, Yuru Li2, Zhaohui Li2, 3, Chao Lu4, Yikai Su1*, and Lu Sun1* 1State Key Lab of Photonics and Communications, Department of Electronic Engineering, Shanghai Jiao Tong University, Shanghai 200240, China 2School of Microelectronics Science a...

work page 2013