Active Optics–Freeform Segment Mirror Replications from a Deformable Matrix^†

Round 1

Reviewer 1 Report

1. The current paper although is showing novelty in the proposed design, it lacks the main aspects of a research article.
2. First of all, the authors need to use updated images and better quality. The authors can use any CAD software to redraw Figures 1 and 4 or at least tidy them up, they seem to be copied from an old file with minimal resolution quality.
3. There is no proper literature review conducted in this work, the authors need to provide at least half a page of propre critical literature review, talk about past studies related in some wat to this work and provide some introduction about applications, techniques, past and old novel techniques attempted by other researchers in the field of the manuscript.
4. The manuscript is written with each paragraph made from 2 lines or so which his not a proper way to write a manuscript. The authors should provide proper formatting for paragraphs and merge smaller paragraphs of less than 4 lines together with other paragraphs.
5. The authors should omit the full name of the paper in the body of the manuscript such as in lines 41-42.
6. Figure 2 add scale bar to the images.
7. Please add a list of nomenclature at the end of the paper for all the symbols and abbreviations used in the manuscript.
8. Figure 3 add (a) (b) and (c)
9. Figure 4 add (a) and (b)
10. Figure 5 add (a) (b) and (c)
11. Please use the correct symbol of degree in the manuscript and not the letter O as a superscript.
12. The overall formatting of the paper should be checked
13. There is no critical discussion of the developed device, compare its performance or efficiency, explain trends observed in the reported results.
14. References are a mess! Different formats, different line type, reference 6 containing an abstract?
15. Overall, I think this submission should be changed to a short communication.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

The first Author wrote a very interesting book published with Springer and concerning active optics in astronomy, so that some extension and the literature overview mandatory in this paper could be partially adopted from this monograph. The Reviewer would be also interested in the recent progress of this research area as the specialist in theoretical and computational mechanics. 

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

All questions answered, no further comments. 

After reviewing this article I think it can be considered as a communication article but not a research article. 

This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.

Round 1

Reviewer 1 Report

This manuscript concerns optics, and particularly, freeform – mirrors designed with the use of elastically deformable matrix. Although the subject is quite interesting, then the manuscript must be remarkably improved. 

Firstly, the literature is very skimpy. The book by Timoshenko is classical and known also for the students. The Author have published some papers before related to the same matter, like "Active optics in astronomy - modeling of deformable substrates: freeform surfaces for FIREBaal and MESSIER: by Gérard Rene Lemaitre, Journal of the Mechanical Behavior of Materials, https://doi.org/10.1515/jmbm-2018-2008 and this is not depicted in this work. It would be instructive to highlight the new aspect while comparing to the previous works. A review of the literature would be necessary. 

Equation (7) is very simplified description of the stress state in the thin plate under consideration and could be replaced with more accurate results, i.e. obtained with the use of the Finite Element Method. It seems that some better model has been presented in Hairen Wang, Mingzhu Zhang, Yingxi Zuo, and Xianzhong Zheng, "Research on elastic modes of circular deformable mirror for adaptive optics and active optics corrections," Opt. Express 27, 404-415 (2019). 

Finally, some error analysis of this optical device would be interesting for the readers of this journal as some novelty with respect to the previous works. 

 

Author Response

Revised paper ‘’ photonics-1462557’’:

Please notice that

• my revised reply is sent in PDF file,
• and the proposed  modifications are in green color.

Best regards,

Gerard R. Lemaitre

Author Response File: Author Response.pdf

Reviewer 2 Report

Thank you for submitting your paper. The work done here draws attention to a significant subject in Active optics. I have found the paper to be interesting. However, several issues need to be addressed properly before the paper is being considered for publication. My comments including major and minor concerns are given below:

1. Please consider reviewing the abstract and highlight the novelty, major findings, and conclusions. I suggest reorganizing the abstract, highlighting the novelties introduced. The abstract should contain answers to the following questions:
2. What problem was studied and why is it important?
3. What methods were used?
4. What conclusions can be drawn from the results? (Please provide specific results and not generic ones). Please use numbers or % terms to clearly shows us the results in your experimental work. Please expand the abstract.
5. The authors are strongly advised to check the following site: https://www.mdpi.com/journal/photonics/instructions for article format according to the journal standards.
6. Where is the introduction?
7. If “1. Generating a telemeter mirror pair for CFHT CassaHawEC spectrograph” is the introduction then the introduction is short, generic and does not provide critical review, it can be expanded, please provide more in-depth review of past studies similar to your work and highlight research gaps and critical discussion between different works.
8. Please consider citing articles related to your work from mdpi journals
9. The authors write so many small paragraphs, it makes it difficult to maintain flow readability of the article, please combine all smaller paragraphs into larger ones. For example, lines 24-50 combine into one larger paragraph.
10. Please improve the quality of Fig.1 consider redrawing it or using a higher resolution images instead.
11. Referencing format is incorrect, please check the guidelines for authors and article format.
12. Add scale bars for figure 2
13. Figure 3 is not clear and have poor resolution especially the two graphs on the left side.
14. The results are merely described and is limited to comparing the experimental observation and describing results. The authors are encouraged to include a more detailed results and discussion section and critically discuss the observations from this investigation with existing literature.
15. Conclusion can be expanded or perhaps consider using bullet points (1-2 bullet points) from each of the subsections.

Author Response

Revised paper ‘’ photonics-1462557’’:

Please notice that

• my revised reply is sent in PDF file,
• the proposed  modifications are in green color,
• 1 and Fig.3-left that are with improved quality,
• the caption of Fig.2 includes an additional text for the dimension (i.e. for the scale).

Best regards,

Gerard R. Lemaitre

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

This manuscript is indeed interesting, nevertheless an overview of the existing works and results should be more extensive. This is a condition to make a final decision. The Reviewer is not the Author and does not serve for finding the works corresponding neither to the principal issue of the paper nor the methods used to achieve the research goals. 

Reviewer 2 Report

0. Introduction 26  numbering should start from 1 not zero

Line 28 " that we had no time to present before because of a lack of time." remove this, it is uncessary information. you can just say that the word was done long time ago and now you can present the work content.

The authors are still not using proper referencing format.

The authors appear to ignore most of the questions raised, even simple ones as improving figures quality and adding scale bars.

The paper can not be accepted if the authors are not willing to make minimum effort to improve their article.

author response file is missing, its just a copy of the revised manuscript. The authors must provide a proper replies to reviewers comments showing their answers step by step for each question raised.