A Plasmonic Modulator with High Modulation Depth Based on the Dual-Control Mechanism

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

 The authors propose a hybrid substrate-dielectric-silicon-graphene structure, which can achieve periodic control of carrier density on graphene through chemical doping of silicon gratings, and the overall control of carrier density by applying the external voltage between substrate and graphene. The numerical results show that the optical transmittance can reach 54.6 dB when the grating length, width, period, and working wavelength are 54 nm, 30 nm, 60 nm, and 8 μm, respectively. The work have a promising application and the manuscript is well written, i would recommend this paper to be published in photonics if the following problems are addressed.1) It would be better if the materials selected in figure 1 could give the reasons?2) More information should be given in the simulation model.3) As a type of micro nano optical devices, how can this work be processed in the laboratory? Suggest the author to provide a flowchart.

4) There are some language problems in the text. I suggest the authors find a native English speaker or ask professional editing service for content revision.

Author Response

Thank you for all constructive suggestions. We have revised the manuscript according to these helpful suggestions, the detail please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Thank you for the work. Could the authors please address the following comments before publication:

• In the introduction, the authors should better emphasize the features using graphene.  
• Why was CaF2 chosen as the dielectric layer over other insulators? Can the authors discuss more about this?
• How do you apply the voltage between the graphene and quartz substrate? Isn’t the quartz an insulator?
• In Section 3, the authors discuss optimization for each design parameter. Please include the assumptions made in the simulations.  For instance, what was the assumed period and width when the authors optimized the length? Similar to 3.2, 3.3, 3.4.
• Since each design parameter may be correlated, the authors should consider the correlation between each design parameter in the simulation.
• After the simulation, what is the optimal design to achieve the best performance?
• The authors should compare the performance of their proposed structure with other published works.  
• The authors should highlight the unique features of their design more clearly to support its significance better.
• The label of Ef in Figure 9(c) should be 0.9eV.
• Overall, the authors should have more detailed discussion on their proposed structure. How does the structure make the better performance and etc. 

Author Response

Thank you for all constructive suggestions. We have revised the manuscript according to these helpful suggestions, the detail please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The manuscript titled "A Plasmon Modulator with High modulation Depth based on the Dual-Control Mechanism" presents a hybrid substrate-dielectric-silicon-graphene
structure, which can achieve periodic control of carrier density on graphene through chemical doping of silicon gratings, and the overall control of carrier density by applying the external voltage between substrate and graphene. The numerical results show that the optical transmittance can reach 54.6 dB when the grating length, width, period, and working wavelength are 54 nm, 30 nm, 60 nm, and 8 μm, respectively. The modulation depth of the modulator is optimized greatly by combining the above control mechanisms together. This structure will have a potential application in optoelectronic sensing, optoelectronic detection and light modulation. The manuscript is well-structured and provides a clear explanation of the theoretical background.
However, there are a few points that need clarification or further investigation:

1. Can the theory of this paper be further extended to other two-dimensional material systems? For example, a new type of two-dimensional material borophene has attracted wide attention recently. Researchers have realized a series of new phenomena in the borophene system, such as flat-band Friedrich-Wintgen bound states in the continuum, and dynamic control of polarization conversion based on borophene. If borophene is used instead of graphene in the manuscript, similar modulation performance can be achieved?
2. Generally speaking, the performance of modulator, such as modulation depth, is usually closely related to the magnitude of the local field enhancement in the structure. Therefore, it would be pertinent to investigate whether the authors have accounted for the effects of localized field enhancement on the modulator’s performance in their theoretical framework.
3.Has the author considered preparing the device experimentally? Can we supplement a general experimental scheme?
4.Related studies have shown that in a graphene-dielectric metasurface, light-matter interactions can be enhanced by quasi-bound states in the continuum. Which is also a hybrid structure of dielectric and graphene, what is the difference between them?

Overall, the manuscript is a valuable contribution to the field of modulators and the rapidly developing field of 2D material optoelectronics. The authors are encouraged to address the above points to further strengthen the manuscript.

Comments for author File: Comments.pdf

Author Response

Thank you for all constructive suggestions. We have revised the manuscript according to these helpful suggestions, the detail please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

This review article presents a plasmon modulator with a high modulation depth based on a dual-control mechanism. The overall structure is relatively complete, and the logic is clear. However, there are still some aspects that need to be improved and refined. Therefore, this manuscript can be accepted and published in Photonics after the following suggestions.

 

1. Firstly, I think that the discussion on the limitations of existing research in the introduction is a bit brief. In the introduction, the quantitative advantages of the dual-control mechanism compared with traditional single-regulatory methods have not been clearly stated. I suggest that the author supplement comparative data (such as modulation depth) to clearly demonstrate the specific performance improvements achieved by the dual-control mechanism.

 

2. The detailed description of the three-dimensional model (Figure 1) is insufficient. It is recommended that the author explain the rationality of choosing CaF₂ as the dielectric layer.

 

3. The parameter optimization of the simulation results (such as the grating length of 54 nm and the grating period of 40 nm) lacks the support of theoretical basis or empirical formulas. It is recommended to introduce a theoretical model to explain the rationality of the parameter optimization.

 

4. When describing the simulation model, the author should supplement information about the simulation software, its version, and the boundary conditions.

 

5. The citation format of the references should be consistent. It can follow the format of Reference 2.

Author Response

Thank you for all constructive suggestions. We have revised the manuscript according to these helpful suggestions, the detail please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Comments and Suggestions for Authors

Thanks for the work. The authors have addressed my concerns.