Holographic Optical Lenses Recorded on a Glassy Matrix-Based Photopolymer for Solar Concentrators
Round 1
Reviewer 1 Report
The article presents a comprehensive overview of recent years research in holographic solar concentrators and identifies the key challenges among which is the identification of an appropriate material for recording of the HOEs. The application is very interesting and it imposes further strict requirements towards the material and the devices. The proposed material is very promising, especially its thermal stability, dynamic range and ability to be coated on a lightweight plastic substrate.
The experimental results are solid and worth publishing, but some improvements of their presentation are compulsory, before that. Below I have included some questions /suggestions:
1) The figures generally require improvement- at the moment they don't have a coherent look, text size, axis labels size, background (some have a background grid included, some don't) , the colour coding is not coherent (for example figure 16). These should be made consistent in the manuscript.
2) The authors comment on the shrinkage of the material - maybe they can discuss if some compensation is possible at the design stage;
3) Shouldn't the grating on Figure 3 be slanted?
4) How many cycles were included in the temperature study experiment?
5) The discussion section needs to be improved. Currently it presents some results, that should be in the results section. The discussion should be expanded and made in the context of previous studies and target values.
6) Figure 7 -what is the size of the probe beam?
7) Figure 9 - colour scale not included
8) It will be very beneficial to include a short summary of the chemical composition of the material (not just referring to a previous article).
After these comments/questions are addressed I will be happy to recommend the article for publication.
Author Response
We thank the Reviewer for her/his useful comments and constructive suggestions, which allowed us to improve the consistency and the readability of our manuscript. Our replies to the Reviewer comments are reported in the attached file.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
The paper is well written and can be of interest. Anyway i recommend standardizing the style of the figures. Some are well done, others are not, such as fig. 7 It is obvious that the figures were made by different people.
Author Response
We are grateful and we thank the Reviewer for her/his useful comments and constructive suggestions. We have improved and standardized the figures in the revised manuscript.
Reviewer 3 Report
See attached
Comments for author File: Comments.pdf
Author Response
We thank the Reviewer for her/his useful comments and constructive suggestions, which allowed us to improve the consistency and the readability of our manuscript. Our replies to the Reviewer comments are reported in the attached file.
Author Response File: Author Response.pdf
Reviewer 4 Report
This manuscript is well organized and demonstrates the study of holographic optical lenses by a photopolymer. I have minor comments that would help to improve the manuscript.
- Figure 1. It would be helpful to readers to understand the procedures if the authors show pictures and diagrams instead of the flow chart.
- Figure 6 and Figure 13. The words are too small to read. Please increase the font size.
Author Response
We thank the Reviewer for her/his useful comments and constructive suggestions, which allowed us to improve the consistency and the readability of our manuscript. The paper has been modified according to the Reviewer requests. In red are reported our replies to the Reviewer comments.
This manuscript is well organized and demonstrates the study of holographic optical lenses by a photopolymer. I have minor comments that would help to improve the manuscript.
- Figure 1. It would be helpful to readers to understand the procedures if the authors show pictures and diagrams instead of the flow chart.
We changed Figure 1 and we really hope this new version con be helpful to readers to better understand the procedures.
- Figure 6 and Figure 13. The words are too small to read. Please increase the font size.
We have improved and standardized the figures in the revised manuscript.
Round 2
Reviewer 1 Report
My comments and suggestions have been addressed and I can recommend the paper for publication.
Reviewer 3 Report
See attached
Comments for author File: Comments.pdf
