Propagation Characteristics of Hermite–Gaussian Beam under Pointing Error in Free Space

Round 1

Reviewer 1 Report

Grammatical errors were found, authors need to re-check overall manuscript

Please add results and conclusions in the Abstract

Authors need to strongly define the contribution of the manuscript

Authors need to add some drawbacks of the proposed method

Please add simulation parameters in a table

Some references are out-of-date, please change it with recent references

Author Response

Thank you for your careful review. Our responses to your comments are attached. Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Thank you for your efforts. A strong work combining theory and simulation.

I have some comments that must be considered in the modified manuscript.

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1) Both (Abstract) and (Conclusion) must include some numerical values of the (main) results.

2) Draw a flow chart (or block diagram) to describe your procedure. This is very useful to follow your (strong) analysis.

3) You have a good comparison between theory (analysis) and simulation (Monte Carlo).... But, I do not see any comparison with previously published work. At least, state how can you judge your results are in the correct range.

4) At the end of your discussion, you write (In order to achieve better reception efficiency for HG beam, we should control the transmission parameters). This is a general sentence. Please, recommend or suggest the values of all parameters for a good and stable operation (or performance).... You can collect this in a table, or any means.

5) Write some future directions as extension to this work.

Author Response

Thank you for your careful review. Our responses to your comments are attached. Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 3 Report

In this paper authors propose a closed-form expression for the irradiance of the HG beam in the presence of pointing errors. The proposed analytical expressions are verified with Monte Carlo simulations. 

I have the following concerns.

a) Please provide some practical applications where the derived results are useful.

b) In several parts of the text the writing should be further elaborated.

c) Please provide more details on MC simulations used to verify analytical results

Author Response

Thank you for your careful review. Our responses to your comments are attached. Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

    I think this manuscript, entitled “Propagation characteristics of Hermite-Gaussian beam under 2 pointing error in free space,” should not be published as a regular paper of photonics: The novelty of the manuscript seems not to reach the level of publication. Below, I provide the comments for the manuscript. I hope these comments help the authors to improve the manuscript.

1. The authors only consider the pointing error. If the authors consider the atmospheric-induced fading, which also affects the irradiance of the laser beam and thus the performance of FSOC, the novelty of the manuscript would be improved. At least, the authors should justify why the authors only consider the pointing error. 

2. The authors should show the process for deriving the theoretical equations. It was appreciated if the authors could explain some special techniques used to derive these equations.

3. In equation (7), the subscrips s and p represent x or y and m and n, respectively. However, these subscripts are used in the right-hand-side of the same equation. I guess, some expression would be needed. 

4. In Section 4, the authors derive the effective spot size and location of the local extreme value of the average irradiance. These derivations seem slightly straightforward. It was appreciated if the authors could express some knowledge extracted from the derivations.

5. The legend in Fig. 11 seems wrong. All colors represent D’1. The authors must correct the correspondence; red for D’1, blue for D’2, and green for D’3.

Author Response

Thank you for your careful review. Our responses to your comments are attached. Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 4 Report

I appreciate Author's effort to improve the manuscript according to my comments. I agree to publish the manuscript in its present form.