Generation of Flat Optical Frequency Comb Using Cascaded Electro-Optic Modulators

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This paper presents an efficient method for generating optical frequency combs and combines neural networks and Bayesian optimization algorithms to search for the optimal flatness parameters. The content is comprehensive, and the experimental design is reasonable. After appropriate modifications to the following issues, it is recommended for publication in ‘Photonics’:

1. The formulas lack labels; the third formula in the entire text on line 96 seems to have a problem. Please check it carefully.

2. There is a formatting issue on line 84 of the manuscript. It is recommended to revise the formatting issues throughout the text.

3. It is suggested to appropriately increase the citation of references, especially those related studies in the past five years.

4. The conclusion can be more focused on summarizing the main findings and their implications, rather than restating the methodology and results obtained in the experiment. Consider highlighting the most significant contributions and how they advance the field.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

This paper proposes the use of neural networks to optimize the parameters of the modulator and thus improve the flatness of the optical frequency comb. However, the paper lacks experimental validation, and in particular, does not clearly account for the source of the dataset. If the dataset is only obtained through simulation, the results in the paper will be very different from the experimental results, which will greatly weaken the persuasiveness of the paper. Therefore, the authors need to address the following questions:

 1. Specific parameters of the modulator need to be given, especially the extinction ratio of the modulator, which will affect the flatness of the optical frequency comb.

 2. The actual electro-optical modulator is asymmetric, which makes the response of the modulator to the signal is imperfect. Therefore, the authors need to experimentally obtain enough data to optimize accordingly. And the optimization results need to be verified experimentally. The flatness improvement in the paper is not obvious, therefore, it is not convincing to improve the flatness of the optical frequency comb only by simulation.

 3. The results of cascading three phase modulators are poor, why is that? Is it possible to use a phase shifter to change the phase of the RF signal to improve the flatness?

 4. There are many reasons affecting the flatness of the optical frequency comb, including defects in the modulator, mismatch in the time window between the phase of the RF signal and the input optical signal, and so on. Have the authors considered these issues in their simulations? Do the parameters in the simulation match the actual situation?

 

 

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The reviewer recommends a major revision for the paper. See the comments in the attachment.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have addressed all the reviewer's comments. The reviewer recommends this paper be accepted in the current version.

Author Response

We are grateful for the invaluable feedback, and we look forward to the opportunity to improve our manuscript in response to your guidance. Once again, thank you very much for your comments and suggestions.

Thank you and best regards.

Author Response File: Author Response.docx