A Band-Switchable and Tunable THz Metamaterial Based on an Etched Vanadium Dioxide Thin Film

Round 1

Reviewer 1 Report

In the manuscript, the authors proposed tunable THz metamaterial employing VO₂ thin film. Importantly, the work shows both the theoretical model of the metadevice and its experimental verification. The concept of the work has been carefully developed, however, before it is ready for publication, I would like to ask the authors to refer to a few important issues:

1. In the introduction, starting from line 44, the authors mention tunable THz metamaterials, mentioning a few materials on which these concepts are based. Unfortunately, this description is incomplete, the authors overlooked some important and well-described active/phase-change materials and their application in active THz metadevices, i.e. liquid crystals (Liquid Crystals 43.8 (2016): 1120-1125), superconductors (IEEE Sensors Journal 21.13 (2021): 15187-15195), MoS2 (Scientific reports 6.1 (2016): 1-9), etc. In my opinion, the authors should expand the description with currently available technologies based on the above-mentioned active materials and then justify the use of VO₂ in the proposed model.
2. The description of the simulation model needs to be supplemented. I suggest the authors insert a table with the parameters (perimittivities, conductivities/losses) of all materials used in the construction of the metadevice. The current version of the description is a bit confusing. Which parameters were constant and which changed as a function of frequency? What simplifications were used in the theoretical model of the metadevice? Please explain.
3. What are the reasons for the discrepancies between the simulation and experimental results (i.e. resonance frequency shift and change in transmittance’s amplitude)?
4. What should be done to improve the parameters of the device, especially its tunability and amplitude modulation?

Author Response

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Reviewer 2 Report

A band switchable and tunable terahertz (THz) metamaterial based on a vanadium dioxide (VO2) thin film was proposed in the THz frequency regime. I think paper is interesting, in this relation, I would propose some minor changes as follows:

1. Authors should justify usage of vanadium dioxide for the metamaterial structure under consideration.
2. Font size in Figures 7, 8 should be increased.
3. Authors are missing some recent articles in the field, such as
   Investigation of Hyperbolic Metamaterials, etc.
4. Authors should highlight novelty of their work in comparison with the state of the art.

Author Response

I've attached the response letter

Author Response File: Author Response.pdf