Switchable Dual-Function Terahertz Metamaterial Device Based on Vanadium Dioxide
Round 1
Reviewer 1 Report
Correct the symbol of vanadium dioxide (VO2) through out the manuscript as VO2.
Author Response
Thank you for your suggestions, we have revised the manuscript.
Author Response File: 
Author Response.docx
Reviewer 2 Report
Xiang et al. proposed a dual-functional terahertz metamaterial device using phase change material vanadium dioxide (VO2). The proposed device has the ability to switch its functionality between an absorber and a polarization converter in the THz band. My comments/questions for the authors are listed below.
I. What is the novelty of the work? Why authors think selected THz range is important. Please add some description related to this.
II. Authors used VO2 I would suggest it's better if they write 2 in subscript.
III. The introduction section can be improved by discussing different other materials platforms and design geometries previously reported in the THz range. A few suggestions are, doi.org/10.1364/OME.409677, doi.org/10.3390/photonics9050335, doi.org/10.1364/AO.438237.
IV. Authors should also discuss the oblique angle response for both the absorber and polarization converter.
V. Please provide more details for the numerical simulations. Which software is used? Is it a unit-cell response or finite-size device is simulated?
VI. Please carefully revise the whole manuscript for grammar and spelling mistakes.
Author Response
Thank you for your suggestions, we have revised the manuscript.
Author Response File: Author Response.docx
Reviewer 3 Report
The submitted paper “Switchable dual-function terahertz metamaterial device based on vanadium dioxide” by X. Mingjia and T. Yunjie is devoted to simulations and of electromagnetic response of a layered metamaterial incorporating VO2 square rings. The authors run the simulations for two cases, namely when VO2 is metallic (high conductivity state) and isolating state. In the first case the structure works as efficient THz absorber and in the second as a polarizing reflector. In standard manner for the research works of such kind the simulations are also run for various topological parameters of the subwavelengh elements. The CST MWS code was used. The obtained results seem to be new, but the study would be much more valuable with experimental realization and measured THz transmission/reflection spectra.
In my opinion, the submitted paper could be published in Coatings in its present form.
Author Response
Thank you for your review and for your approval.
Author Response File: Author Response.docx
Reviewer 4 Report
A dual-functional terahertz metamaterial device is proposed based on the temperature-controlled phase transition properties of vanadium dioxide. I think paper is interesting, I would recommend some changes as follows:
- Authors should compare the obtained results with the experimental outputs.
- The choice of the vanadium oxide should be justified.
- Authors are missing some recent articles in the field such as Investigation of hyperbolic metamaterials.
- The chosen frequency range should be justified.
- The topic is relevant to the field, however, Authors should stress novelty of their work in comparison with others.
- Authors are mentioning absorption in the manuscript, in this relation its origin should be described and justified.
Author Response
Thank you for your suggestions, we have revised the manuscript.
Author Response File: Author Response.docx
Reviewer 5 Report
The paper numerically investigated switchable metamaterials using VO2. However, the paper is not matured and there are some unclear points. Here are my comments.
1. There is no relation between the temperature and the conductivities of VO2. Why do the authors claim that the proposed structure is switchable?
2. Many papers regarding reconfigurable metamaterials using VO2 have already been published. The novelty is unclear.
3. Please add materials such as VO2 and Au to Fig. 1.
4. As for Fig. 3(b), the concentrated energy between the unit cells seem no to be the same. Please add the discussion on this point.
Author Response
Thank you for your suggestions, we have revised the manuscript.
Author Response File: Author Response.docx
Round 2
Reviewer 5 Report
The authors did not address the main point. As for the response 1, the thermal property of VO2 is well known. How can the temperature of the proposed metamaterial be changed by absorbing the light and what temperature can be achieved? There is no discussion about the thermal properties of the proposed metamaterials. Therefore, the main concept cannot be demonstrated by the present manuscript.
Author Response
Thank you for your suggestions, we have revised the manuscript.
Author Response File: Author Response.docx
