GaAs Linear Polarizer with a High Extinction Ratio for Extended Short-Wave Infrared Detection

Round 1

Reviewer 1 Report

Dear editor,

The manuscript, "GaAs linear polarizer with a high extinction ratio for extended short-wave infrared detection", written by Leidong Shi et al. proposed single-layer, all-dielectric and diatomic metasurface composed of GaAs-based PCM and PSM operating in the SWIR atmospheric window (1-3 μm). The reviewer believe that this paper can be considered for publication in Photonics. There are some comments.

1.       Has the GaAs linear polarizer proposed by the authors been made into a finished product, and does the polarizer performance match the simulation results?

2.       Why choose 2100-2200 nm as the working wavelength? Is there any special significance?

3.       Is the height of PCM consistent with the height of PSM?

4.       Is there a requirement for the number of PCM and PSM arrangements? How many is optimal?

5.       The statement "The first control and adjustment of the polarization state in the short-wave infrared (SWIR) band (1~3 μm) has been achieved" needs further confirmation.

Best wishes

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

This manuscript proposes an all-dielectric diatomic metasurface for the polarization and phase modulation of electromagnetic waves in the short-wave infrared (SWIR) band. The metasurface comprises a pair of GaAs nanopillar and nanocube, and its structural parameters can be adjusted to regulate the polarization state and accomplish wavefront shaping. The authors systematically investigated the changes in transmittance, extinction ratio, and degree of linear polarization (DOLP) concerning the operating wavelength, incident polarization angle, PSM diameter, and PCM rotation angle via theoretical analysis and FDTD numerical simulation. The results demonstrate that this diatomic metasurface can function as a linear polarizer, and its polarization angle relies on the PCM rotation angle and the PSM radius. Additionally, the maximum values of transmittance, extinction ratio, and DOLP can reach 93.76%, 40.99 dB, and 0.99, respectively. Furthermore, by suitably adjusting the structural parameters, the phase-tuning range of the incident light can be expanded, potentially enabling the use of this metasurface for extended SWIR polarization detection.

 

1.               There are also other infrared materials (ie Sapphire, ZnS, ZnSe, etc.) that transfer in the SWIR band if presented at the board level without direct integration into the detector. At line 55, the author should provide some more information on infrared material selection.

 

2.               The authors calculated Transmission using the transfer matrix. In the proposed structure, complex scattering coefficients should be shown as a schematic illustration.

 

3.               It is recommended that the authors provide a clear explanation of the roles of PSM and PCM in their proposed metamaterials, including their optical functionalities when used individually or in combination (Composed of only PSM or PCM, a combination of the two). Additionally, the manuscript should elaborate on the advantages of the proposed PSM and PCM-based metamaterials compared to existing metamaterial structures.

 

 

4.               As the manuscript concerns the SWIR band detector, the authors should provide comments on the scalability of widely used detection materials, such as InGaAs and InSb. Furthermore, it is suggested to provide additional information in lines 252 to 258.

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 3 Report

Comments on the manuscript

 

The manuscript proposes an all-dielectric diatomic metasurface made of GaAs nanopillar and nanocube, which can efficiently control and change the polarization state at the infrared regime. At the wavelength of 2125 nm, the metasurface achieves high transmission efficiency, extinction ratio, and linear polarization degree. These metasurfaces have potential applications in infrared polarization detection.

 

Overall, the paper is scientifically intriguing and the simulation findings make contributions to the field of polarization control metasurfaces. Additionally, the paper is technically sound, with well-supported conclusions and assertions. Therefore, the manuscript is within the scope of Photonics and I recommend publishing it, provided that the minor points are addressed.

 

1.      Quoting “Although the metal grating structure at subwavelength based on the surface plasmon oscillation effect can obtain a high extinction ratio, the transmittance of such polarizers is generally low due to the high optical loss of metal materials [7, 8].” The introduction contains some problematic claims, such as the assertion that metal grating structures based on surface plasmon oscillation have low transmittance due to the high optical loss of metal materials. However, this is likely only true for certain short wavelength ranges like VIS and NIR, and there are examples of metal polarization converters that can achieve broadband high transmission in the THz range. Please see [Grady, Nathaniel K., et al. "Terahertz metamaterials for linear polarization conversion and anomalous refraction." Science 340.6138 (2013): 1304-1307]. Please be careful.

2.      Diatomic metasurfaces design is a key issue in this work. I am surprised that some recent advances in diatomic metasurfaces (dielectric and plasmonic) were not mentioned at all [ Liang, Yao, et al. "Full-stokes polarization perfect absorption with diatomic metasurfaces." Nano Letters 21.2 (2021): 1090-1095; Deng, Zi-Lan, et al. "Diatomic metasurface for vectorial holography." Nano letters 18.5 (2018): 2885-2892].

3.      In Section 3, which covers the design and numerical simulation, it is unclear which simulation software was employed. Did the authors utilize FDTD numerical, CST Studio, COMSOL, or other software?

 

4.      Figure 4. What is the purpose of utilizing a narrowband high extinction ratio at a radius of 245um for PSM?

Author Response

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Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The manuscript have been well revised, and suitable for publish.