Review Reports

Round 1

Reviewer 1 Report

The present study is very interesting. However, it may be further strengthened by addressing the following queries:

1.      Abstract section, reference citation may be removed. Author may write that the previous study has been done...... However, the same may be discussed the problem statement at the introduction level.

2.      Please see the reference 2 where reference has to be cited, but the statement is given as Follows: The correct name for these excitations that involve charge density oscillations and the associated 172 electromagnetic field is "surface plasmon-polariton", we just abbreviate it for convenience. Please cite the appropriate reference herein.

3.      References style are not uniform.

4.      Literature review should be enhanced in the introduction section.

5.      Authors should compare their work with the published study.

6.      Conclusion part may be included in the abstract section.

Author Response

See attached file.

Author Response File: Author Response.pdf

Reviewer 2 Report

This paper reports a detailed study of Analysis of all-optical generation of graphene surface plasmons by a frequency–difference process. The proposed approach is very meaningful, and the manuscript organization is satisfied. However, some comments are raised, and revisions should be made before the acceptance for publication. My concerns for this manuscript are shown below:
1. The quality of English in this manuscript is currently good. Of course, it needs to some edit, i.e., make all efforts to rectify any grammatical mistakes, typos, double spaces, missing spaces etc.

2. The introduction of the manuscript is missing some details about the nonlinear properties of materials. The authors must motivate the nonlinearity property in the introduction part with suitable references, for example: https://doi.org/10.1142/S021886351950005X

Author Response

See attached file.

Author Response File: Author Response.pdf

Reviewer 3 Report

       This paper reports the theoretical analysis of all-optical generation of graphene surface plamson via frequency–difference process. The optical conductivity which is a key parameter for determining the property of graphene is calculated based on the density-matrix perturbation theory with respect to the second term effect. The general theory and method can be clearly illustrated in this paper. However, the paper conclusion seems confusing for me that the authors only had proved the inappropriate approach of density-matrix perturbation theory for prediction of the experimental observation of NL conductivities, even though the second term effect in Hamiltonian of the electrons is included for correction. However, the authors did not provide the new physics for prediction of experiment results, although the authors also mentioned the hot-electron effects as possible physics mechanism. However, no further works are discussed in current work. In my opinion, the paper should be reorganized by replenishing model with essential physical elements for prediction of the experimental observations of graphene property. Therefore, I suggest the paper can not be published in its current format.

Author Response

See attached file

Author Response File: Author Response.pdf