Design and Fabrication of Highly Selective Polarizers Using Metallic–Dielectric Gratings
, Yi Ning 1,2,3,†, Liang Liu 1,2,3,†, Siyu Dong 1,2,3,*, Yifang Chen 4,*, Zhanshan Wang 1,2,3,5 and Xinbin Cheng 1,2,3,5
Round 1
Reviewer 1 Report
In this manuscript, entitled “Design and fabrication of highly selective polarizers using metallic-dielectric gratings”, the authors proposed a high-performance polarizer using the metallic-dielectric gratings (MDGs). The results are proved by experiments with high TM transmittance ~ 90% and a high extinction ratio ~100:1. In general, I recommend this paper published in Photonics. Some modification suggestions are still needed.
1. Most references are ten years ago, and only four references are of the last three years. The authors should rearrange the previous works and introduce the latest results of gratings.
2. The authors state “And we calculated and compared the refractive indexes of different gratings composed of gold, silver, and aluminum…aluminum had the best polarization selection …”. Could you give the comparison results of this?
3. Optical parameters of the different materials such as SiO2, Al, Si should be displayed explicitly. The simulated RCWA method is also suggested to explain more clearly.
4. As the authors discussed, the thickness of the side walls is inessential in the final performance. Some theoretical explanations should be added. It is perfect if the authors could give the simulated electric filed distributions. This will help the paper improved as a scientific research, rather than seeming like an engineering report.
Author Response
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Reviewer 2 Report
The authors designed and fabricated high-performance metallic-dielectric grating (MDG) for TM polarization with the following experimental results: transmission of about 90% and extinction ratio of about 100:1. The manuscript is well-organized and written. However, I have some comments regarding the numerical results and optimization as follows:
. The response from a variation of the thickness of different layers to enhance the polarization performance, as stated in lines 88-89, was not presented in the manuscript. These results are also important to be shared in the manuscript.
. The results related to the comparison of the polarizations performance for different gratings composed of gold, silver, and aluminum, as mentioned in lines 89 and 90, were also not presented in the manuscript. These results are important to be shared in the manuscript.
. The Authors used particle swarm optimization algorithm to reach the best MDG configuration. It would be interesting to know the parameters used to run this algorithm and some of its performance.
. Did the silicon layer take into account those results presented in figures 1(b)-(d)?
Author Response
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Reviewer 3 Report
The authors present the design and fabrication of a metal-dielectric grating that acts as a polarizer in the near infrared spectral range. The performance they achieved, i.e. the transmission ratio of both polarizations as well as the total transmission, shows that the system can be a useful component for transmission imaging systems. The results are sound. But there are some details that require improvement.I propose to accept the manuscript for publication after improving the following points:
(1) The authors should clearly define "TE" and "TM". In text books these terms are used in the context of reflection and transmission under obliqe incidence where "transverse" is related to the incidence plane. This is not applicable here as the authors regard perpendicular incidence. So it would be natural to relate "transverse" to the direction of the grating lines. But according to the presented transmission data, the authors seem to define it the other way. So, in order to avoid confusion, please add a remark for defining "TE" and "TM".
(2) In Figure 2, the labeling is a bit confusing, as two types of labels (a)-(d), and (i), (ii) are used. Can the authors change the style of the figure to make the structure more clear, e.g. by putting (a)-(d) into boxes?
(3) In Fig. 3a an arrangement with a laser is shown for transmission measurement which does not correspond to Figs. 3b,c where spectral data are shown. In the text the authors mention that they used a spectrometer. Therefore, this should be shown in Fig. 3a for consistency.
(4) In the reference list some lower case letters are used where capital letters are required, e.g. Ref. 1. "Ieee Sensors Journal" instead of "IEEE ...".
Author Response
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Reviewer 4 Report
The paper is devoted to theoretical design and experimental fabrication of a high-performance NIR polarizer based on a metal-coated dielectric grating. The details of the technology developed by the authors to fabricate a high-aspect-ratio nano-scale grating and metalizing it appropriately is described in detail. Unfortunately, the performance of the prototype was not as high as in the simulations (extiction ratio of 102 but not 104). In section 2, the authors did not provide intermediate optimization results but only the final configuration of the structure. Therefore, it is not clear which of the structure papameters affect the extiction ratio. More information on theoretical bachkground would be helpful. Nevertherless, I rate this work very highly and wish the authors success in improving their experimental results in future.
Author Response
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Round 2
Reviewer 2 Report
The authors have improved the manuscript and addressed all my comments. In my opinion, the current manuscript can be accepted for the journal.
