Strong Coupling Based on Quasibound States in the Continuum of Nanograting Metasurfaces in Near-Infrared Region

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper investigate the realization of Friedrich-Wintgen bound states in the continuum (FW-BICs) in nanograting metasurfaces, demonstrating strong coupling phenomena in the near-infrared regime with exceptional optical performance. Furthermore, the work achieves chiral frequency splitting in circular dichroism spectra through strategic interaction between the metasurface and chiral dielectric layers, offering a promising platform for advanced biophotonic applications. While the manuscript demonstrates significant potential for chiral optical devices and biosensing technologies, several critical revisions are required to enhance scientific rigor and clarity. I suggest that the authors revise this paper based on the following suggestions.

 

1. Although the manuscript notes that the refractive index data for gold is sourced from Ref. [39], it fails to explicitly clarify whether the dispersion and losses of metals (e.g gold, silver) are fully incorporated in the simulations. How these factors influence the FW-BIC coupling behavior .
2. In view of the large number of chart data included in the text, it is recommended to add descriptive subtitles to all figures.
3. The text points out that the wavelength and incident angle of FW-BIC increase linearly with the thickness of the SiO₂ layer, but only a limited number of data points (400-460 nm) are displayed. Does this linear relationship hold over a wider parameter range？
4. Figure 2(e) actually shows the reflection spectra of silicon dioxide with thicknesses of 400 nm and 460 nm, but the text describes it as "from 400 nm to 460 nm", which is inaccurate.
5. The terms"quasi-bound states in the continuum (qBIC)"and"Friedrich-Wintgen BICs"lack definitions and mechanistic explanations upon their first mention. I suggest that the author add the concept of "Quasi bound states in the continuum" and the physical mechanism of "Friedrich-Wintgen BICs" in the introduction, and cite relevant references.
6. Some terms (such as "qBIC", "quasi-BIC", "Q-BIC") are mixed. It is suggested that the author use the full term of "Quasi bound states in the continuum" at first time it appears, and its abbreviation "qBIC" or "quasi-BIC" is used thereafter.
7. The paper points out that "our work demonstrates a significantly larger CD signal under the same Pascal parameters and with a thinner chiral dielectric layer[35,38].". it is recommended to add a table comparing CD values, layer thicknesses, and Q-factors.Include normalized metrics.
8. Some references lack volume and page number information, and it is recommended to check the reference format comprehensively.
9. Some research backgrounds need to be added, such as: Opto-Electron Adv 7, 240039 (2024). Opto-Electron Sci 3, 240011 (2024). Opto-Electron Sci 3, 240012 (2024). Opto-Electron Adv 7, 230194 (2024). Journal of Lightwave Technology, 2022, 40(1): 136-142. Opto-Electron Adv 7, 240095(2024).

Author Response

Please see the attachment. Appreciate.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Please see the attached file

Comments for author File: Comments.pdf

Comments on the Quality of English Language

The paper requires English editing (see Review)

Author Response

Please see the attachment. Appreciate.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

I recommend it can be accepted.

Reviewer 2 Report

Comments and Suggestions for Authors

After the revisions I belive the paper can be published