Numerical Study of a Polarization Selective Visual Optical Switch

Round 1

Reviewer 1 Report

I have the following notes:

• What does mean "field of color"?
• Explain all acronyms in their first usage (CMOS etc.)
• The Introduction section contains 23 references, but the authors did not compare their results with relevant references? I suggest adding the main contribution of this article is ...
• The rest of this paper is structured as follows ...
• The Introduction section is difficult to read and get general information. The article deserves the State of Art section.
• Section 2 starts with the Figure without any text or details. Section 2 missed relevant information about design and features about research, which led to this shape and materials etc.
• Why do you need Section followed by subsection without any words?
• Use the same structure in reference Fig. vs fig. vs Figure.
• The statement "as is known to all" is not proper for the research article.
• Line 114: 1, 2, and 3
• Line 144: In general,
• Tables 1 and 2 contain relevant results of the research. However, the authors mentioned their content in one sentence.
• What is your future work?

 

The overall merit of the article is weak. On the one hand, the authors researched with relevant results their presentation does not reflect the Journal recommendations and conditions. Please, improve your paper in a significant point of view, especially, with appropriate text, results in discussion, your improvements in comparison with related works and explain to us why your work is better than others? I am not a native speaker, but obtain the main idea of the article is quite impossible in the form of the article. I have to suggest MAJOR REVISIONS and reconsider the article in a new review round.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The authors present a nano-structured device, which is polarisation dependent and where the maximum contrast between the on and off state can be tuned in a certain range. In addition, a nice method is presented for the characterisation of the structure. There are many interesting aspects in this paper, but the structure is confusing, the colour characterisation is nice but in contrast to the single-wavelength switching operation, the background on the intended application is not really clear as well as the need for a sub-wavelength structuring (since any polarisation filter based on metal gratings will do the same). I recommend major revisions that should address at least the following points:

1. Add to the title that it is just a numerical study
2. Describe the intended application for the structure, which also explains the need for sub-wavelength structuring.
3. Introduce the whole structure in a more systematic way. Also add some more information on the numerical tools and the limitations.
4. Motivate the parameter choice: The hole diameter, the choice of material etc are not obvious.
5. Add a comment on the angular dependence. The hole, e.g., is only circularly symmetric in the case of orthogonally incident light.
6. Motivate and explain the introduction and use of the colour characterisation. In my opinion, it is a nice idea, but not relevant for a structure that is intended to be used at one particular wavelength. In this case many colour characterisations can have the same contrast at a particular wavelength.
7. The electrical field distributions are nice and prove that the simulations had really been done, but I doubt a bit their added value to the paper. The main argument during the discussion is the position of the charges. But since this is mainly the same for all presented structures, I could not obtain much insight from it -- especially compared to the space they occupy.
8. Fig. 4 shows a strong decrease of the switching property: For wavelengths beyond 550nm, both polarisations are either similarly transmitted or even reversely. Is this a physical phenomenon or an artefact from the numerical simulation. It appears that for longer wavelengths the structures become even more sub-wavelength, which may be the reason for the behaviour/problems...
9. The study of the different materials seems a bit random by just choosing Ni and Si. I guess it would be more interesting to focus on material properties such as conductivity or epsilon_r. Since the results are purely numerical, one should use the advantage that material properties can be chosen at will in order to follow a certain systematic.
10. Finally, the last aspect with the colour characterisation appears to be quite independent and not fully fitting to the rest of the article. It might be split into two contributions or the idea of this method should be explained in more detail in order to make the article more consistent.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

The article presents interesting issues whose resulates can be applied in practice.
I have only a few comments:
- Line 58 - the analyzed structure in the figure 1 in the Z direction has a different scale than in other directions,
- Line 156, Line 169 and Line 172 - Si is not metal but semiconductor.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

I do agree with the authors, which improved the paper well. On the other hand, they still mix Introduction Section with Related Works (State-of-Art) Section. Why did not you provide general information for the Introduction Section and the references details into the State of Art? 

 

I chose only Minor revision because the authors have to add "THE MAIN CONTRIBUTION PARAGRAPH" in comparison with related works. Tell us why your work is important and relevant, and what did you improve in comparison with related works. 

 

Please, follow the template of the Journal with reference style. 

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The article has not really changed significantly. Most of the raised concerns still remain. E.g., it is not really clear what the application should be: There is no mechanism to change the structure adaptively, so how should switching work without changing the polarisation of the incident light? Why is the change of the transmission peak important: Shall light of continuous spectrum be transmitted (which suggests the study of the colour characterisation) or individual wavelengths (which would be a more traditional switching scheme)?

The studies give no real insight about trends and optimisation directions. The parameters are just chosen based on available or common materials without a direct study which properties of the materials have which effect. The influence of the angle of incidence is not mentioned, at all. But it is vital since it breaks symmetries or will also change the transmission characteristics with resulting shifts of transmission peaks etc. 

All in all, I must still judge the contribution in more or less the same way as in my last review (knowing that the other reviewers seem to have a different view on the subject). Most of the listed issues have not really included in the document or have not really been explained.

Author Response

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Author Response File: Author Response.pdf

Round 3

Reviewer 2 Report

My opinion has not really changed a lot, but the author’s response and the fact that my co-reviewers have accepted the paper had brought me to the conclusion to accept it with minor revisions, as well.

I would, however, include a sentence on the fact that the structure itself is completely passive and for switching operation another device for polarisation rotation is needed. This could also be included in the sketch.

Author Response

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Author Response File: Author Response.pdf