Sub-Diffraction Focusing Using Metamaterial-Based Terahertz Super-Oscillatory Lens

Round 1

Reviewer 1 Report

In this paper, the authors theoretically and experimentally demonstrate a metamaterial-based terahertz super-oscillatory lens (SOL) that can achieve 0.27 times the diffraction limit. Before considering publication, here are some problems that need to be addressed.

 

1. What are the differences between the proposed design and reference 43?

2. What is the advantage of the proposed SOL compared with the previously reported work? I suggest the authors list the performance comparisons of the proposed meta-device and the other designs.

2. Are there any physical limitations regarding the size of the focal spot along the transversal axes? What is the efficiency variation of the SOL concerning the resolution increment?

3. To illustrate the physical mechanism, the spatial distribution of transmission and phase over the SOL mask should be given.

4. What is the stepping precision of the translation stage and the dynamic range of the VNA?

5. In Fig.8 (b), what caused the discrepancies between simulation and measurement? Is it possible to replace the oversized probe antenna with a smaller needle probe?

6. The frequency-dependent experimental results should be given to demonstrate the spectral performance of the proposed SOL.

Author Response

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Author Response File: Author Response.docx

Reviewer 2 Report

I think the manuscript has reach the standards of applied science.

 

Author Response

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Reviewer 3 Report

In this work “Sub-diffraction Focusing using Metamaterial-based Terahertz Super-oscillatory Lens” a metamaterial-based super-oscillatory lens (SOL) is presented which is shown to be capable of generating multiple focal points smaller than the diffraction limit. In this research, the numerical results as well as experimental data are provided and compared. The proposed device is highly effective for terahertz applications.

This manuscript is written with well-explained physics, and it is supported with sufficient formulations which help the readers to clearly understand the concept. However, I believe a minor revision I required before the manuscript can be published in the Journal of Applied Sciences.

Comments:

1-      For the fabricated device, an SEM image or any microscopical image is required in order to show the experimental parameters such as diameter, period, or duty cycle. In this case, it would be clearer how the fabricated device parameters are compared to their simulated counterparts.

2-      In the presented manuscript there are 20 (out of 46) references that are not affiliated with Makoto Nakajima. This has to be considered and the number of self-citations should be reduced.

3-      It would be more interesting and practical if the authors present FWHM in x and y directions for the proposed fabricated lens.

4-      In addition to the intensity distribution, I would recommend the authors show the profile of phase distribution in radians for the optimized parameters of the circular lens.

Comments for author File: Comments.pdf

Author Response

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Author Response File: Author Response.docx