Design and Analysis of Orthogonal Polarization Point Diffraction Pinhole Plate

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

This article provides a detailed modeling analysis of the pinhole plane in point diffraction interferometers, including the influence of pinhole size, material on the intensity (maximum aperture angle) of reference spherical waves, wavefront phase error, polarization characteristics, and the period, depth, and duty cycle of the grating. On the basis of modeling analysis, corresponding experimental verification was carried out, and the accuracy of the measurement results was verified by constructing a test optical path. The measurement results were basically consistent with those of the Zygo interferometer, which is a complete task.

       However, there are some areas that need to be modified and further supplemented in this manuscript. The current manuscript does not fully reflect the innovation of the author's work. It seems that only a series of parameter convenience and analysis have been carried out on the point diffraction pinhole plane in the point diffraction interferometer using the FDTD method. It is recommended to appropriately enrich the discussion of the results. The author analyzed the pinhole plane of point diffraction based on the FDTD method, but the final experiment only verified the accuracy of wavefront measurement, and the simulation analysis results lacked a clear relationship with the experiment. In addition, the manuscript also has the following issues:

1 The expression and content in the article need to be revised. For example:

In line 49, the reference is labeled as [10], but in reality it is [18], published in 2011 instead of 2010, and the full name of the author's affiliation is Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences instead of Changchun Institute of Optical Precision Machinery and Physics, Chinese Academy of Sciences。

In lines 259-260，Why do you repeat " The diffraction wavefront error is 0.0048λ" three times

In line 172, what does l refer to in the time step length Δ t=l/2c

2  In Figure 5, The horizontal axis of Figure A is 00, 03, 0..., while Figure B is 0.0, 0.3, 0.6. Is this an analysis result indicating that the two images are not the same structure or is the image drawn incorrectly?

3   Lines 224-242 discuss the influence of pinhole size on the maximum aperture angle for generating spherical wave intensity. However, for the sake of rigor, the definition and analysis method of this maximum aperture angle should be supplemented

4  Section 3.3, why does the sub wavelength periodic structure affect the diffraction wavefront, and how is this analysis result obtained; And simulating sub wavelength micro/nanostructures usually only analyzes a few period sizes, without considering the size of the wavefront that can be considered

5  Why use fitting results based on measurement results instead of direct measurement results in Figure 13

Based on the above considerations, we believe that the current manuscript does not meet the publishing requirements. The author should make appropriate revisions to the manuscript in response to the aforementioned issues and the opinions of other reviewers, and make a new decision on whether the manuscript is worthy of acceptance after the revisions are completed.

Comments on the Quality of English Language

The expression and content in the article need to be revised. For example:

In line 49, the reference is labeled as [10], but in reality it is [18], published in 2011 instead of 2010, and the full name of the author's affiliation is Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences instead of Changchun Institute of Optical Precision Machinery and Physics, Chinese Academy of Sciences。

In lines 259-260，Why do you repeat " The diffraction wavefront error is 0.0048λ" three times

In line 172, what does l refer to in the time step length Δ t=l/2c

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

The authors presented a pinhole plate design for the point-diffraction interferometer for wavefront measurements. Then they utilized the finite-difference time-domain method to simulate and improve the specific design of the orthogonal polarization point diffraction pinhole plate. The optimized plate has a Cr film thickness of 150 nm, a hole diameter of 2 um, a period of 150 nm and a width of 100 nm for the wire grid. The authors further performed an experimental demonstration of the interferometer, offering a peak-to-valley value error of 0.0028λ, which suggests the quality of the wavefront measurement. The methodology is sound and well-documented, providing confidence in the reproducibility of the findings.

1.      The authors quantitatively analyzed the performance of the designed pinhole plate using diffraction wavefront error and extinction ratio. How is the performance of the demonstrated pinhole plate compared to existing publications besides the commercial ZYGO interferometer?

2.      How does the simulated diffraction wavefront error correlate to the experimental peak-to-valley value error? What is the accuracy of the ZYGO interferometer? Does the experimental result have a comparable performance to the simulation?

3.      There are a few places with grammatical errors that require the authors' attention. For instance, in line 200, there is redundancy in the last sentence. The authors write, ‘so the metal Cr was finally selected as the orthogonal The metal grating layer of the OP-PDPP is finally selected.’ And in line 312, ‘in order to make the pinhole plate diffraction wavefront error is small, it should be’.

Comments on the Quality of English Language

 There are a few places with grammatical errors that require the authors' attention. For instance, in line 200, there is redundancy in the last sentence. The authors write, ‘so the metal Cr was finally selected as the orthogonal The metal grating layer of the OP-PDPP is finally selected.’ And in line 312, ‘in order to make the pinhole plate diffraction wavefront error is small, it should be’.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

Please refer to the Word document.

Comments for author File: Comments.pdf

Comments on the Quality of English Language

A few corrections have been mentioned in the Word document.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf