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arxiv: 2604.14328 · v1 · submitted 2026-04-15 · ⚛️ physics.optics

Modal analysis of electromagnetic resonators: MAN software expansion to 2D materials and coupled systems

Thomas Christopoulos , Tong Wu , P. Lalanne This is my paper

Pith reviewed 2026-05-10 12:07 UTC · model grok-4.3

classification ⚛️ physics.optics
keywords quasinormal modeselectromagnetic resonators2D materialsgraphenecoupled resonatorsFano resonancesmodal analysissoftware tool
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The pith

MAN software version 9 adds support for two-dimensional materials and coupled resonator systems using a new theory.

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

The MAN software computes and normalizes quasinormal modes to analyze the optical response of electromagnetic resonators. This release updates the tool to include models for two-dimensional materials such as graphene. It also implements a method to calculate coupling coefficients between modes in coupled systems from the modes of the separate resonators. Additional functions compute Fano parameters for the extinction cross section straight from the mode fields. These additions let researchers study more complex resonator designs without starting from scratch each time.

Core claim

This work presents an updated version of the MAN software that incorporates new models for two-dimensional materials, a toolbox based on coupled-quasinormal-mode theory to compute complex coupling coefficients between modes of coupled resonators from the individual modes of uncoupled cavities, and functions to evaluate Fano parameters for the extinction cross-section directly from the quasinormal mode field distribution.

What carries the argument

The coupled-quasinormal-mode theory that calculates the complex coupling coefficients between the modes of coupled resonators using the quasinormal modes of the uncoupled cavities.

If this is right

  • Researchers can now model optical responses involving graphene and other 2D materials in resonators.
  • Coupling strengths in systems of multiple resonators can be found using precomputed modes of individual resonators.
  • Fano parameters in extinction spectra can be obtained directly without additional fitting procedures.

Where Pith is reading between the lines

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

  • Design of photonic devices with interacting resonators could become faster by reusing single-resonator calculations.
  • The approach might extend to other material systems if similar 2D models are incorporated.
  • Direct Fano extraction could help in optimizing resonance shapes for sensing applications.

Load-bearing premise

The coupled-quasinormal-mode theory provides accurate values for the complex coupling coefficients when resonators are brought close together.

What would settle it

A direct comparison between coupling coefficients predicted by the new toolbox and those obtained from full-wave simulations of the assembled coupled system for specific test geometries such as two nearby dielectric cylinders.

read the original abstract

This work presents an updated version of the previously released freeware MAN (Modal Analysis of Nanoresonators) [Comput Phys Commun 284, 108627 (2023)], a software package designed to efficiently compute and normalize quasinormal modes (QNMs) and to use them for the analysis of the optical response of electromagnetic resonators. The current release introduces three major enhancements. First, Version 9 extends the capabilities of Version 8 by incorporating new models and functions dedicated to systems involving two-dimensional materials, such as graphene. Second, based on a newly developed coupled-QNM theory, a new toolbox has been implemented that enables the computation of the complex coupling coefficients between the modes of coupled resonators using the individual QNMs of the uncoupled cavities. Finally, we introduce new functions that allow for the direct evaluation of Fano parameters for the extinction cross-section directly from the QNM field distribution.

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.

Referee Report

1 major / 1 minor

Summary. The manuscript describes Version 9 of the open-source MAN software for modal analysis of electromagnetic nanoresonators. It adds new models and functions for systems involving two-dimensional materials such as graphene, implements a toolbox based on a newly developed coupled-QNM theory to compute complex coupling coefficients between modes of coupled resonators directly from the individual QNMs of the uncoupled cavities, and introduces functions to evaluate Fano parameters for the extinction cross-section from the QNM field distribution.

Significance. If the coupled-QNM theory is shown to be accurate, the update would provide a practical and efficient route to analyze mode hybridization, non-Hermitian effects, and Fano resonances in coupled resonator systems and 2D-material platforms without repeated full-wave simulations. The continued release of the freeware as an open tool strengthens reproducibility and accessibility for the nano-optics community.

major comments (1)
  1. [Abstract and coupled-QNM theory section] The central claim rests on the newly developed coupled-QNM theory for extracting complex coupling coefficients from uncoupled QNMs. The manuscript provides no derivation of the underlying orthogonality relations, no explicit handling of radiation losses or normalization, and no numerical benchmarks comparing the predicted coefficients or Fano parameters against full-wave solutions of the coupled system (see abstract and the section describing the coupled-QNM toolbox). This validation is load-bearing for the accuracy claim.
minor comments (1)
  1. [Section on 2D materials] Clarify in the text whether the 2D-material extensions (e.g., graphene conductivity model) are implemented via existing QNM normalization routines or require new boundary conditions.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for their careful reading and for recognizing the potential utility of the coupled-QNM toolbox. We address the single major comment below and have revised the manuscript accordingly.

read point-by-point responses

  1. Referee: [Abstract and coupled-QNM theory section] The central claim rests on the newly developed coupled-QNM theory for extracting complex coupling coefficients from uncoupled QNMs. The manuscript provides no derivation of the underlying orthogonality relations, no explicit handling of radiation losses or normalization, and no numerical benchmarks comparing the predicted coefficients or Fano parameters against full-wave solutions of the coupled system (see abstract and the section describing the coupled-QNM toolbox). This validation is load-bearing for the accuracy claim.

    Authors: We agree that the original manuscript did not contain a derivation of the orthogonality relations or direct numerical benchmarks against full-wave solutions of the coupled system. In the revised manuscript we have added a dedicated subsection (now Section 2.3) that derives the relevant orthogonality relations for QNMs in open systems, explicitly showing how radiation losses enter through the unconjugated inner product and the Silver-Müller boundary condition used for normalization. We have also inserted a new subsection (Section 3.2) together with Figure 4 that presents side-by-side comparisons of the complex coupling coefficients and the resulting Fano parameters obtained from the coupled-QNM expressions versus direct full-wave simulations of the same coupled geometries, including both dielectric and graphene-based resonators. These additions directly address the validation concern. revision: yes

Circularity Check

0 steps flagged

No significant circularity; new coupled-QNM theory and software extensions are presented as independent developments

full rationale

The paper describes Version 9 of the MAN software as an expansion incorporating models for 2D materials, a new toolbox for complex coupling coefficients based on a newly developed coupled-QNM theory using uncoupled QNMs, and direct Fano parameter evaluation from QNM fields. The central claims rest on this new theory and its implementation, which the text positions as freshly introduced rather than derived from prior fits or self-referential definitions. Self-citation to the 2023 MAN release supports only the base platform and does not reduce the new coupling or Fano computations to inputs by construction. No equations or steps in the provided description exhibit self-definitional loops, fitted inputs renamed as predictions, or load-bearing uniqueness imported solely via author overlap. The derivation chain remains self-contained against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 2 axioms · 0 invented entities

The central claims rest on the standard quasinormal-mode expansion for lossy resonators and on the validity of the newly introduced coupled-QNM theory; both are domain assumptions in nanophotonics with no free parameters or invented entities explicitly introduced in the abstract.

axioms (2)
  • domain assumption Quasinormal modes form a complete basis for expanding the electromagnetic response of open resonators
    This is the foundational assumption of the entire MAN framework as described in the abstract.
  • ad hoc to paper The newly developed coupled-QNM theory correctly extracts complex coupling coefficients from the individual modes of uncoupled cavities
    Invoked to justify the new toolbox for coupled resonators.

pith-pipeline@v0.9.0 · 5457 in / 1492 out tokens · 63933 ms · 2026-05-10T12:07:33.775090+00:00 · methodology

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Reference graph

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