Color-Adjustable Devices Based on the Surface Plasmons Effect

Round 1

Reviewer 1 Report

Authors present a study regarding utilization of SPs to achieve adjustable coloring devices. The topics is interesting. However, several improvements need to be made:

• Title looks confusing. Maybe 'Color-adjustable devices based on the surface plasmons effect' or the like is more easier to understand?
• Both abstract and conclusion only mentioned that authors use different metal nanoparticles in the nanoholes. However, authors only present the results using Al metal particels and holes. Thus, authors should also study other metals and comment how other metal materials behave in such pattern or more specific terms should be given here.
• In introduction part, when rendering background in the SPs field, another more recent interesting device application of utilizing SPs to absorb the light based on nanowire array structures should also be included. e.g. Journal of Photonics for Energy 6 (4), 042502, 2016
• Authors mentioned that torus nanoparticles renders wider color distribution and better color contrast from their simulation results. Authors should also provide some theoretical explanation or find some real-world device performance to provide more insight.

Author Response

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Author Response File: Author Response.pdf

Reviewer 2 Report

The manuscript titled “Adjustable coloring device based on the surface plasmons structure color” by Kui Wen et al describes an adjustable coloring device, which is composed of a template and metal nanoparticles The template is the periodic circle-hole arrays on the aluminum film. By adding different nanoparticles in the nanoholes they shifted the plasmon resonance wavelengths. They also make the plasmon resonance wavelength shifts by filling dielectric materials with different refractive indices in the holes of the template. The calculation results are reasonable and clear. However, there are several unclear points to be addressed. Thus, I think that this manuscript may be acceptable after reasonable revision.

Comments
1. To make the discussion clear, the authors should firstly calculate plasmon resonance spectra of isolated nanoparticles by changing sizes and refractive indices.
2. Why the plasmon resonance wavelengths of the holes do not show spectral shifts in Fig. 2?
3. The authors should explain the effect of the coupling between the plasmon of nanoparticles and the plasmon of the holes on the spectral shifts. The comment is related with the comment 1. 
4．The authors should evaluate scattering loss, absorption loss, and incident angle dependences. These are important for practical applications.
5. The Q factors are very bad. Is it possible to improve the Q factors of the systems? This point should be discussed.
6. The experimental method for changing the refractive indices should be proposed.

Author Response

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Author Response File: Author Response.pdf

Reviewer 3 Report

In this paper, untitled Adjustable coloring device based on the surface plasmons structure color, the authors present the modulated optical response of a metamaterial with different sizes, patterns, and compositions. Their main theoretical results indicate that the surface plasmons distribution in the hole can be changed by adding nanoparticles with different structures on the template.

 

Comments:

 

• Can you please add this following reference in the Introduction section: Plasmonic- and dielectric-based structural coloring: from fundamentals to practical applications.

 

• In the Design and Modeling section, the acronyms FDTD is not defined.

 

• In the Design and Modeling section section, in the transmittance equation, the in and out power flux are not clearly defined.

 

 

Based on all these comments, I conclude that this paper can be published as it is.

Author Response

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Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors well revised the manuscript. Thus, I can recommend the manuscript for publication. 

By the way, the separation of  scattering loss and absorption loss will be important for such color devices. See e.g. Nano Lett. 10, 1398 (2010) and Phys. Rev. B 99, 235409 (2019).