A Theoretical Study on Mid-Infrared Difference Frequency Generation Based on Periodically Poled Thin-Film LiNbO3
Round 1
Reviewer 1 Report
The author theoretically studied difference frequency generation using QPM in TFLN. The manuscript is clear but the novelty is limited. It suffers from the lack of a comprehensive introduction, clear formulation and a good reasoning. The reviewer thinks that the manuscript must be re-submitted with changes while the following points should also be added, or revised.
What is the advantage of QPM? Complete your short literature review including the citation of other previously-proposed QPM-based articles mentioning how to increase flat BW, e.g.:
1- 10.1109/JLT.2007.909862
2- 10.1109/JSTQE.2011.2136324
Comment on possible mode-matching in the WG, apart from the QPM, to realize DFG? Why do you use QPM?
A theoretical paper without the formalism for numerical FDE simulation, any citation to previous publication and so on? Do you use a commercial software? How do you validate it?
Why are TM modes are considered if you need only TE mode for QPM in x-cut LN. Discuss it.
Fig. 4b: Why does the highly slanted waveguide (alpha=60) result in maximum confinement? Discuss it.
Dimensions in Eq. (8) do not seem correct. What is the relation between E and P?
What is the reason for the dip in the confinement curve (Fig. 6b)? Discuss it.
Provide n_eff curves at signal and idler wavelengths, too.
What about the waveguide loss? Facet reflectivites?
How can you flatten the BW?
Comment of QPM fabrication error.
Line 464: Pp=100dBm?
Theta or alpha in Fig.1? Check the axes (x,y,z) on the figure.
Author Response
We thank the reviewer for reading and carefully reviewing our work. We are delighted to see your valuable suggestions on our work. In what follows, we will provide detailed responses to the individual questions in PDF file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
Comments for author File: Comments.pdf
Author Response
We thank the reviewer for reading and carefully reviewing our work. We are delighted to see your valuable suggestions on our work. In what follows, we will provide detailed responses to the individual questions in PDF file.
Author Response File: Author Response.pdf
Reviewer 3 Report
I suggest minor revision for this paper and here are my comments:
1-A comparison table is needed. The authors should compare their work with at least 5-10 previously published work in the same area in 2020-2023.
2-Which Software did the authors use? What are the mesh sizes and the boundary conditions? Authors should add this info in the revised manuscript.
3-The confinement factor vs W for different values of pitch Λ should be simulated and given with the physics behind.
4-The sentence started in line 163 was not completed.
5-Some equations are given without references. Please mention their related references.
6-What are the applications? Please give a brief paragraph in the introducion mentioning the applications.
Author Response
We thank the reviewer for reading and carefully reviewing our work. We are delighted to see your valuable suggestions on our work. In what follows, we will provide detailed responses to the individual questions in PDF file.
Author Response File: Author Response.pdf
Round 2
Reviewer 1 Report
Fig. 1 seems z propagating NOT y propagating.
Author Response
Thank you for your review of our article and the question you raised has been revised. Please see pdf file for details.
Author Response File: Author Response.pdf
Reviewer 2 Report
all the critical points were adressed.
Author Response
Thank you for your review of our article.
