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REVIEW 4 major objections 5 minor 45 references

High-order virtual gain for optical loss compensation in plasmonic metamaterials

T0 review · 4 major / 5 minor · reviewed 2026-08-07 · deepseek-v4-flash

Pith's one-line read Synthetic waves with high-order virtual gain slow signal decay and suppress noise in loss-compensated plasmonic metamaterials.

desk verdict Qualitative story is plausible and worth refereeing, but the headline 20–30-fold suppression claim is not yet supported by the presented evidence. read the letter →

arxiv 2505.21976 v1 pith:CA3UIGOK submitted 2025-05-28 physics.optics

classification physics.optics PACS 42.70.Qs42.25.Bs78.20.Ci
keywords high-ordervirtualgaincomplexfrequencyexcitationlosscompensationplasmonicmetamaterialsplasmon-inducedtransparencysyntheticwavesnoisesuppression
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

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

The reading

This paper proposes a way to compensate optical losses in plasmonic metamaterials without the rapid signal decay that limits conventional complex-frequency excitations. The idea is to synthesize high-order virtual gain waves, whose nth-order waveform decays as $t^{n-1}e^{-\beta t}$ rather than $e^{-\beta t}$, so the useful signal lingers longer while the same loss-compensation physics is preserved. The paper derives the scaling of the target and unwanted terms, and demonstrates in a plasmon-induced-transparency metamaterial roughly 20-fold (and up to 30-fold) suppression of unwanted spectral oscillations compared with standard complex-frequency waves. If the scaling holds, the approach extends loss compensation to extreme-loss systems where the required virtual gain would otherwise wipe out the signal.

What carries the argument

The central object is the nth-order synthetic wave $E_n(t) = t^{n-1}e^{-i\tilde{\omega}t}\theta(t)$ and its Fourier decomposition $E_n(t) = (n-1)!\int e^{-i\omega' t}/[2\pi(i\tilde{\omega}-i\omega')^n]\,d\omega'$. This makes the response a high-order pole problem: the residue theorem yields the target $t^{n-1}\varepsilon_L(\tilde{\omega})e^{-i\tilde{\omega}t}$ plus a truncation term of order $(i\tilde{\omega}-i\tilde{\omega}_0)^{-n}$ and a finite-frequency-range term decaying as $(\omega_\Delta^n t)^{-1}$. The order $n$ is the tuning knob that trades a modest algebraic delay of the target against the ability to use virtual gains much closer to the damping bound.

What would settle it

Measure the time-resolved synthesized displacement field of a Lorentzian permittivity for $n=1,2,3$ at a fixed $\beta$ and bandwidth $\omega_\Delta$, and check whether the unwanted finite-frequency artifact decays as $t^{-1}\omega_\Delta^{-n}$ independently of the spectral window shape; a decay exponent that depends on the window function, or a noise floor that does not drop by the predicted factor when $n$ increases by one, would falsify the central scaling claim.

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Extended reading notes

Core claim

For an nth-order synthetic wave built from a multi-monochromatic combination, the synthesized displacement field is $D_n(\tilde{\omega},t) \approx t^{n-1}\varepsilon_L(\tilde{\omega})e^{-i\tilde{\omega}t} + D_{n,\mathrm{TIS}}(t) + D_{n,\mathrm{FFL}}(t)$, where the target term scales as $e^{-\beta t}t^{n-1}$, the truncation-induced term as $e^{-\gamma t/2}$, and the finite-frequency-range term as $(\omega_\Delta^n t)^{-1}$. Because the target now carries the algebraic prefactor $t^{n-1}$, its decay is slowed relative to the $n=1$ complex-frequency case, so at the optimized measurement time the target amplitude is larger. The paper claims this is what makes higher-order virtual gain robust in extreme-loss settings, and supports it with measurements on a plasmon-induced-transparency metamaterial in which the recovered transmission spectra show fewer oscillations and a higher target-to-unwanted ratio.

Load-bearing premise

The central quantitative prediction rests on the assumption that the finite-frequency-range error is exactly the pole-dominated form $|D_{n,\mathrm{FFL}}(t)| \approx (n-1)!|\cos(\omega_\Delta t)|/(\pi t\omega_\Delta^n)$ from a hard, symmetric truncation of the spectral window; if the experimental window shape, detector bandwidth, or Kramers-Kronig phase retrieval distort this balance, the predicted optimal snapshot times and the size of the high-order advantage change.

Editorial extensions

If this is right

  • At a fixed target-to-unwanted ratio, higher orders n permit virtual gains $\beta$ much closer to the damping bound $\gamma/2$, extending loss compensation into the extreme-loss regime where conventional complex-frequency waves fail.
  • The synthesis formula is linear-response agnostic, so the same high-order scheme applies to transmission, scattering, and polarization spectra of photonic, phononic, or acoustic systems.
  • Because the finite-frequency artifact decays as $(\omega_\Delta^n t)^{-1}$, increasing the order n relaxes the required measurement bandwidth for a given noise floor, or equivalently allows the same bandwidth to be used at a later snapshot time.
  • In the plasmon-induced-transparency experiment, the recovered transparency peak is sharper and less oscillatory, which the paper argues should improve the sensitivity of plasmonic and phononic sensors that rely on spectral line shapes.
  • The approach can be combined with existing synthetic complex-frequency experiments by replacing the $n=1$ weighting with an $n>1$ weighting in the multi-frequency sum.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Because the $(n-1)!$ prefactor grows factorially, the practical benefit of increasing n saturates; the paper itself notes saturation near $n=3$, so the next test is to map the optimal order as a function of the available frequency window and the damping $\gamma$.
  • The claimed 20-fold versus 30-fold suppression suggests the improvement factor depends on the specific metric and comparison point; a standardized target-to-unwanted ratio at fixed virtual gain and fixed bandwidth across orders would clarify the comparison.
  • The derivation assumes a hard, symmetric frequency truncation and ignores detector bandwidth and phase-retrieval errors from Kramers-Kronig relations; a natural extension is to model realistic window functions, where the pole-dominated finite-frequency estimate may need to be replaced by a window-weighted integral.
  • If the scaling survives in nonlinear or time-varying measurements, the same high-order synthesis could be used to shape signals in integrated photonic circuits, effectively trading spectral bandwidth for temporal contrast in pump-probe or sensing applications.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

4 major / 5 minor

Summary. The manuscript introduces 'high-order virtual gain' (HVG) synthetic excitations E_n(t)=t^{n-1}e^{-iω̃t}θ(t) for loss compensation in plasmonic metamaterials. The authors show that the nth-order synthesized response contains a target term t^{n-1}ε_L(ω̃)e^{-iω̃t} whose envelope decays as e^{-βt}t^{n-1}, while the truncation (TIS) and finite-frequency (FFL) artifacts decay as e^{-γt/2} and (ωΔ^n t)^{-1} respectively. They argue that choosing higher n permits larger virtual gain β at the same target-to-unwanted ratio (TUR), yielding narrower compensated resonances. The theory is tested on a Lorentzian permittivity and on a plasmon-induced transparency metamaterial, where the authors claim 20-fold (abstract/summary) or 30-fold (introduction) noise suppression over conventional complex-frequency excitations.

Significance. The qualitative idea that a t^{n-1} prefactor delays the exponential decay of the target signal is simple and elegant, and the multi-frequency synthesis formula Eq. (1) is a useful general tool for any linear response. If the quantitative claims are substantiated, HVG would meaningfully extend synthetic complex-frequency techniques to high-loss systems, with potential impact on superlens imaging, sensing, and polaritonics. The experimental PIT demonstration shows a clear qualitative reduction of oscillations for n=2,3. However, the paper's quantitative claims (β_n values, TUR equalization, 20/30-fold suppression) rest on asymptotic formulas and a snapshot-selection rule that are not validated or precisely defined, and the headline suppression factor is inconsistent between sections. These issues currently prevent the quantitative conclusions from being accepted.

major comments (4)
  1. [Abstract and Introduction] The paper reports '20-fold noise suppression' in the Abstract and Summary but '30-fold greater noise suppression' in the Introduction, and no definition of the suppression metric is provided anywhere in the main text or methods. Since this is the principal quantitative claim of the paper, please define the metric (e.g., RMS deviation of the recovered spectrum from a reference, peak-to-peak oscillation amplitude, or TUR improvement) and report a single consistent value with the circumstances of the comparison (same virtual gain, same TUR, or other).
  2. [Theory (derivation of D_FFL and |D_{n,FFL}|)] The finite-frequency artifact is approximated as |D_{1,FFL}(t)|≈|cos(ωΔ t)|/(π t ωΔ) and |D_{n,FFL}(t)|≈(n-1)!|cos/sin(ωΔ t)|/(π t ωΔ^n). This asymptotic form is stated without derivation and assumes a symmetric hard-truncated integration window and an integrand whose endpoint values are constant. For the Lorentzian parameters used in Fig. 1 (ω0=ωp=2, γ=0.05, ωΔ=1), the endpoint values of ε_L differ substantially (ε_L(ω0−ωΔ)≈2.3, ε_L(ω0+ωΔ)≈0.2), so the simplified formula is not obviously valid. Because the β_n values and TUR equalization in Fig. 2 are derived from this formula, please provide a derivation and validate it against direct numerical integration of D_n on the actual frequency grid used in the experiment (including FTIR sampling and any window function).
  3. [Theory and Fig. 2(b)] The TUR-equalization procedure is ambiguous. The text states that the different β_n are chosen to give 'the same TUR around 1% at their respective optimized evolution moments', while the optimized moment is defined earlier as the crossing of |D_TIS| and |D_FFL|. Since the FFL term oscillates (cos/sin), the crossing condition has multiple solutions, and the figures do not specify which crossing is used. Moreover, for the stated parameters, simple order-of-magnitude estimates of the target and TIS amplitudes at the crossings do not appear to yield a common TUR across n=1,2,3 (e.g., for n=3, β=0.492γ, the TIS amplitude at t=0 is ~3×10^10 while the target grows only as t^2 e^{-βt}, making TUR=1 at the crossing unlikely). Please present the exact equations used to select β_n and the snapshot times, and list the resulting TUR values numerically.
  4. [Theory near D_n approximation] The central decomposition D_n(ω̃,t) ≈ t^{n-1}ε_L(ω̃)e^{-iω̃t} + D_{n,TIS} + D_{n,FFL} keeps only the leading term from the nth-order residue at ω̃. For n≥2, the residue also generates terms proportional to t^{n-2},..., t^0 with coefficients involving derivatives of ε_L; these lower-order terms decay as e^{-βt} and may be non-negligible at the snapshot times used in Fig. 2 (which are of order 10^2–10^3 γ^{-1}). Please estimate their magnitude or include them in the TUR calculation, and verify that the approximation is accurate over the parameter range used.
minor comments (5)
  1. [Eq. (1)] In Eq. (1), the notation Δω'_k is introduced without specifying whether it is the constant grid spacing; please define it.
  2. [Fig. 1(b)] Fig. 1(b) does not label the axes; adding units for time and for the field magnitudes would improve readability.
  3. [Throughout] The Introduction and Summary contain typos ('suppresion', 'polaritionic'); a proofread is needed.
  4. [References] Reference [6] is listed as a preprint without journal details; if published, please update.
  5. [Abstract] The Abstract's claim of '20-fold noise suppression' should specify the comparison basis (same virtual gain or same TUR) to be reproducible.

Circularity Check

0 steps flagged · score 0.0 of 10

No significant circularity: the t^{n-1} target term is a residue-theorem consequence of the defining waveform, while the paper's actual new claim (suppression of truncation and finite-bandwidth artifacts) is derived and benchmarked independently against n=1.

full rationale

The derivation chain is self-contained. The paper defines the nth-order synthetic wave as E_n(t)=t^{n-1}e^{-iω̃t}θ(t), and the residue theorem then yields D_n(ω̃,t)≈t^{n-1}ε_L(ω̃)e^{-iω̃t}+D_n,TIS+D_n,FFL. Although the t^{n-1} factor in the target term is a mathematical consequence of the nth-order pole and hence is built into the ansatz, this is not a fitted parameter or a renamed observation; it is standard linear-response theory for the defined excitation. The load-bearing new claim is that the unwanted terms D_n,TIS and D_n,FFL do not acquire the t^{n-1} factor and scale as e^{-γt/2} and (ωΔ^n t)^{-1} respectively; that scaling is derived from the high-order residue theorem and finite-frequency-tail integrals, not assumed, and it is tested against the n=1 CFW baseline in both the Lorentz-model analysis and the PIT experiment. Self-citations to the authors' earlier CFW work (Refs. [6], [35], [36]) supply prior methodology and context, but they are not used as an unverified uniqueness theorem or to forbid alternative explanations, and the CFW baseline is also independently established in the literature. The discrepancy between the abstract's '20-fold' and the introduction's '30-fold' noise suppression, and the selection of experimental snapshot times by inspection in Fig. 3(d), are correctness and reproducibility concerns, not circularity. I find no load-bearing circular step.

Assumptions & free parameters 3 free parameters · 4 assumptions · 0 invented entities

The central idea is not circular: it is a derivation from a stated Lorentzian model plus standard complex analysis. The main free choices are the virtual-gain values used to equalize TUR in the theoretical comparison and the experimental β, neither of which is fitted to the claimed outcome. No new physical entities (particles, forces, dimensions) are introduced.

free parameters (3)
  • Per-order virtual gain β_n for equalized-TUR comparison = 0.2γ (n=1), 0.4γ (n=2), 0.492γ (n=3), 0.499γ (n=4)
    Chosen by hand so every order reaches the same ~1% TUR at its optimized snapshot; this equalization drives the FWHM comparison in Fig. 2(d) and is not derived from the physics.
  • Experimental virtual gain β = 200 cm^-1
    Used for all orders in the PIT experiment; the value is stated but not justified or optimized.
  • Lorentzian model parameters ω_p, ω_0, γ = ω_p = ω_0 = 2, γ = 0.05
    Illustrative parameters for the theoretical demonstration in Figs. 1-2; the central claim is not fitted to these numbers, but the quantitative FWHM improvement depends on them.
assumptions (4)
  • standard math Residue theorem and its high-order generalization
    Used to evaluate the synthesized displacement field D_n(ω̃,t) as the sum of pole contributions at ω̃ and at the resonance ω̃0 (Theory section).
  • domain assumption Lorentzian permittivity model for the material response
    The theoretical analysis assumes ε_L(ω) = 1 - ω_p^2/(ω^2 + iωγ - ω0^2 - γ^2/4); real metamaterials may have additional dispersion and spatial dispersion.
  • domain assumption Kramers-Kronig relations reconstruct the phase from transmission magnitude
    Used to obtain φ_M for the measured PIT sample; valid only for causal, passive systems with sufficient bandwidth, and errors propagate into the synthesized polarization.
  • domain assumption Symmetric hard-truncated frequency window (ω0-ωΔ, ω0+ωΔ)
    The FFL bound approximates the finite frequency range as a symmetric interval centered on the resonance; the experimental window shape is not guaranteed to have this form.

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Pith. "Pith review of High-order virtual gain for optical loss compensation in plasmonic metamaterials." pith.science (2026). https://pith.science/paper/CA3UIGOK

@misc{pith2026250521976,
  author       = {Pith},
  title        = {Pith review of: High-order virtual gain for optical loss compensation in plasmonic metamaterials},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/CA3UIGOK}},
  note         = {Machine review of arXiv:2505.21976}
}
read the original abstract

Metamaterials exhibit extraordinary properties yet suffer from pronounced wave dissipation, particularly in optical imaging and sensing systems. Recent advances leveraging complex frequency wave excitations with virtual gain effect, synthesized by multi-monochromatic waves, offer promising solutions for optical loss compensation. However, this approach faces limitations in extreme loss scenarios. The complex frequency wave requires sufficient virtual gain, i.e., temporal attenuation, to offset material loss, inevitably triggering rapid signal decay to zero before reaching a quasi-static state. To address this challenge, we introduce synthetic waves of high-order virtual gain to slow down the decay rate while preserving the loss compensation efficiency. We experimentally demonstrate 20-fold noise suppression in plasmonic resonance systems compared to conventional complex frequency excitations. This approach exhibits broad applicability across diverse fields, including imaging, biosensing, and integrated photonic signal processing.

Figures

Figures reproduced from arXiv: 2505.21976 by the authors.

Figure 1
Figure 1. Illustration of loss compensation with CFW of different virtual gains. (a) [PITH_FULL_IMAGE:figures/full_fig_p011_1.png] view at source ↗
Figure 2
Figure 2. Synthetic excitations of HVGs for loss compensation. (a) Temporal profiles of HVG waves. (b) Temporal evolutions of target (colored solid lines), TIS (colored dashed lines) and FFL (black line) under excitation of HVGs of three different orders, I: n=1, 𝛽 = 0.2𝛾; II: n=2, 𝛽 = 0.4𝛾; III: n=3, 𝛽 = 0.492𝛾. Here the FFL terms in three cases are normalized to the same curve for better comparison. (c) Real and (d) imagina… view at source ↗
Figure 3
Figure 3. Experimental demonstration of recovering plasmonic resonances with HVG [PITH_FULL_IMAGE:figures/full_fig_p013_3.png] view at source ↗

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Works this paper leans on

45 extracted references · 43 canonical work pages

  1. [1]

    J. B. Pendry, Negative refraction makes a perfect lens, Phys Rev Lett 85, 3966 (2000)

  2. [2]

    N. Fang, H. Lee, C. Sun, and X. Zhang, Sub–Diffraction-Limited Optical Imaging with a Silver Superlens, Science (1979) 308, 534 (2005)

  3. [3]

    Z. Liu, H. Lee, Y. Xiong, C. Sun, and X. Zhang, Far -field optical hyperlens magnifying sub-diffraction-limited objects, Science (1979) 315, 1686 (2007)

  4. [4]

    Taubner, D

    T. Taubner, D. Korobkin, Y. Urzhumov, G. Shvets, and R. Hillenbrand, Near -field microscopy through a SiC superlens, Science (1979) 313, 1595 (2006)

  5. [5]

    S. Kim, Y. Peng, S. Yves, and A. Alù, Loss Compensation and Super -Resolution with Excitations at Complex Frequencies, Phys Rev X 13, 041024 (2023)

  6. [6]

    F. Guan, X. Guo, K. Zeng, S. Zhang, Z. Nie, S. Ma, Q. Dai, J. Pendry, X. Zhang, and S. Zhang, Overcoming Losses in Superlenses with Synthetic Waves of Complex Frequency, 2023

  7. [7]

    N. W. Bartlett, M. T. Tolley, J. T. B. Overvelde, J. C. Weaver, B. Mosadegh, K. Bertoldi, G. M. Whitesides, and R. J. Wood, A 3D-printed, functionally graded soft robot powered by combustion, Science (1979) 349, 161 (2015)

  8. [8]

    N. Liu, L. Langguth, T. Weiss, J. Kästel, M. Fleischhauer, T. Pfau, and H. Giessen, Plasmonic analogue of electromagnetically induced transparency at the Drude damping limit, Nat Mater 8, 758 (2009)

Show all 45 references
  1. [9]

    N. Liu, M. Mesch, T. Weiss, M. Hentschel, and H. Giessen, Infrared perfect absorber and its application as plasmonic sensor, Nano Lett 10, 2342 (2010)

  2. [10]

    Rodrigo, O

    D. Rodrigo, O. Limaj, D. Janner, D. Etezadi, F. J. García De Abajo, V. Pruneri, and H. Altug, Mid -infrared plasmonic biosensing with graphene, Science (1979) 349, 165 (2015)

  3. [11]

    K. V. Sreekanth, Y. Alapan, M. Elkabbash, E. Ilker, M. Hinczewski, U. A. Gurkan, A. De Luca, and G. Strangi, Extreme sensitivity biosensing platform based on hyperbolic metamaterials, Nat Mater 15, 621 (2016)

  4. [12]

    Tittl, A

    A. Tittl, A. Leitis, M. Liu, F. Yesilkoy, D.-Y. Choi, D. N. Neshev, Y. S. Kivshar, and H. Altug, Imaging-Based Molecular Barcoding with Pixelated Dielectric Metasurfaces Downloaded From, 2018

  5. [13]

    D. N. Basov, M. M. Fogler, and F. J. García De Abajo, Polaritons in van Der Waals Materials, Science

  6. [14]

    S. I. Bozhevolnyi, V. S. Volkov, E. Devaux, J. -Y. Laluet, and T. W. Ebbesen, Channel plasmon subwavelength waveguide components including interferometers and ring resonators, Nature 440, 508 (2006)

  7. [15]

    R. F. Oulton, V. J. Sorger, T. Zentgraf, R. M. Ma, C. Gladden, L. Dai, G. Bartal, and X. Zhang, Plasmon lasers at deep subwavelength scale, Nature 461, 629 (2009)

  8. [16]

    Fei et al., Gate -tuning of graphene plasmons revealed by infrared nano -imaging, Nature 486, 82 (2012)

    Z. Fei et al., Gate -tuning of graphene plasmons revealed by infrared nano -imaging, Nature 486, 82 (2012)

  9. [17]

    Hu et al., Gate-Tunable Negative Refraction of Mid-Infrared Polaritons, 2023

    H. Hu et al., Gate-Tunable Negative Refraction of Mid-Infrared Polaritons, 2023

  10. [18]

    G. X. Ni et al., Fundamental limits to graphene plasmonics, Nature 557, 530 (2018)

  11. [19]

    S. Xiao, V. P. Drachev, A. V. Kildishev, X. Ni, U. K. Chettiar, H. K. Yuan, and V. M. Shalaev, Loss-free and active optical negative-index metamaterials, Nature 466, 735 (2010)

  12. [20]

    J. M. Hamm, S. Wuestner, K. L. Tsakmakidis, and O. Hess, Theory of light amplification in active fishnet metamaterials, Phys Rev Lett 107, 1 (2011)

  13. [21]

    Sadatgol, Ş

    M. Sadatgol, Ş. K. Özdemir, L. Yang, and D. O. Güney, Plasmon Injection to Compensate and Control Losses in Negative Index Metamaterials, Phys Rev Lett 115, 035502 (2015)

  14. [22]

    Archambault, M

    A. Archambault, M. Besbes, and J. J. Greffet, Superlens in the time domain, Phys Rev Lett 109, 097405 (2012)

  15. [23]

    Ghoshroy, Ş

    A. Ghoshroy, Ş. K. Özdemir, and D. Ö. Güney, Loss compensation in metamaterials and plasmonics with virtual gain [Invited], Opt Mater Express 10, 1862 (2020)

  16. [24]

    H. S. Tetikol and M. I. Aksun, Enhancement of Resolution and Propagation Length by Sources with Temporal Decay in Plasmonic Devices, Plasmonics 15, 2137 (2020)

  17. [25]

    W. K. C. W. M. P. S. W. X. L. X. M. X. L. Yi Yang, Enhancing imaging resolution of superlens through transient illumination, Advanced Fiber Laser Conference 13104, 718 (2024)

  18. [26]

    S. An, T. Liu, J. Zhu, and L. Cheng, Complex -frequency calculation in acoustics with real-frequency solvers, Phys Rev B 111, (2025)

  19. [27]

    D. G. Baranov, A. Krasnok, and A. Alù, Coherent virtual absorption based on complex zero excitation for ideal light capturing, Optica 4, 1457 (2017)

  20. [28]

    H. Li, A. Mekawy, A. Krasnok, and A. Alù, Virtual Parity-Time Symmetry, Phys Rev Lett 124, 193901 (2020)

  21. [29]

    Trainiti, Y

    G. Trainiti, Y. Radi, M. Ruzzene, and A. Alù, Coherent virtual absorption of elastodynamic waves, Sci Adv 5, 1 (2019)

  22. [30]

    S. Kim, S. Lepeshov, A. Krasnok, and A. Alù, Beyond Bounds on Light Scattering with Complex Frequency Excitations, Phys Rev Lett 129, 203601 (2022)

  23. [31]

    Z. Gu, H. Gao, H. Xue, J. Li, Z. Su, and J. Zhu, Transient non-Hermitian skin effect, Nat Commun 13, 7668 (2022)

  24. [32]

    Hinney, S

    J. Hinney, S. Kim, G. J. K. Flatt, I. Datta, A. Alù, and M. Lipson, Efficient excitation and control of integrated photonic circuits with virtual critical coupling, Nat Commun 15, 2741 (2024)

  25. [33]

    Hinney, S

    J. Hinney, S. Kim, G. J. K. Flatt, I. Datta, A. Alù, and M. Lipson, Efficient excitation and control of integrated photonic circuits with virtual critical coupling, Nat Commun 15, (2024)

  26. [34]

    S. Kim, A. Krasnok, and A. Alù, Complex-Frequency Excitations in Photonics and Wave Physics, Science (New York, N.Y.)

  27. [35]

    K. Zeng, C. Wu, X. Guo, F. Guan, Y. Duan, and L. Lauren, Synthesized complex - frequency excitation for ultrasensitive molecular sensing, ELight 4, 1 (2023)

  28. [36]

    Guan et al., Compensating losses in polariton propagation with synthesized complex frequency excitation, Nat Mater 23, 506 (2024)

    F. Guan et al., Compensating losses in polariton propagation with synthesized complex frequency excitation, Nat Mater 23, 506 (2024)

  29. [37]

    Farhi, A

    A. Farhi, A. Mekawy, A. Alù, and D. Stone, Excitation of absorbing exceptional points in the time domain, Phys Rev A (Coll Park) 106, 1 (2022)

  30. [38]

    Farhi, A

    A. Farhi, A. Cerjan, and A. D. Stone, Generating and processing optical waveforms using spectral singularities, Phys Rev A (Coll Park) 109, 1 (2024)

  31. [39]

    Farhi, W

    A. Farhi, W. Dai, S. Kim, A. Alù, and D. Stone, Efficient general waveform catching by a cavity at an absorbing exceptional point, Phys Rev A (Coll Park) 109, L041502 (2024)

  32. [40]

    Tittl, A

    A. Tittl, A. Leitis, M. Liu, F. Yesilkoy, D. Y. Choi, D. N. Neshev, Y. S. Kivshar, and H. Altug, Imaging-based molecular barcoding with pixelated dielectric metasurfaces, Science (1979) 360, 1105 (2018)

  33. [41]

    D. N. Basov, M. M. Fogler, and F. J. García De Abajo, Polaritons in van der Waals materials, Science (1979) 354, 195 (2016)

  34. [42]

    Fleischhauer, A

    M. Fleischhauer, A. Imamoglu, and P. J. Marangos, Electromagnetically induced transparency, Rev Mod Phys 77, 633 (2005)

  35. [43]

    Zhang, D

    S. Zhang, D. A. Genov, Y. Wang, M. Liu, and X. Zhang, Plasmon-induced transparency in metamaterials, Phys Rev Lett 101, (2008)

  36. [44]

    Gralak, M

    B. Gralak, M. Lequime, M. Zerrad, and C. Amra, Phase retrieval of reflection and transmission coefficients from Kramers–Kronig relations, Journal of the Optical Society of America A 32, 456 (2015)

  37. [45]

    Zheng, H

    G. Zheng, H. Mühlenbernd, M. Kenney, G. Li, T. Zentgraf, and S. Zhang, Metasurface holograms reaching 80% efficiency, Nat Nanotechnol 10, 308 (2015)

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