Nonlinearities in Fringe-Counting Compact Michelson Interferometers
Round 1
Reviewer 1 Report
Dear authors,
Your study's focus on investigating the impact of non-linearities on phase extraction in Michelson interferometers is both interesting and relevant to the field. The experimental setup and the theoretical framework chosen for the research demonstrate a good approach. However, I have attached some comments in the PDF file.
Addressing the identified weaknesses will significantly strengthen your paper for publication.
I hope you find my feedback constructive and helpful for refining your work.
Comments for author File: 
Comments.pdf
Only a few typos were found. The paper lacks consistency in explaining abbreviations upon first use, making it challenging for readers unfamiliar with the field to follow the content. Authors should make sure to spell out abbreviations when they are introduced initially (BRS, FSR, ISI). Line 222 "in not entirly" -> "is not entirly". Line 231 "nonlinearirty"
Author Response
We would like to thank the reviewer for their highly constructive and insightful comments. We agree with the reviewer's suggestions and have made changes based on these that we think strengthen the paper. We've made significant extensions to the paper, particularly in the area of evaluating nonlinear effects more broadly, and we have also reworded the title and some sections to better avoid misinterpretation about the purpose of the paper.
A full response to each of the reviewer's points is attached in a separate document. To address the reviewer's supplementary comment about too much reliance on the reader's familiarity with the prior work, we have added more information from the previous paper about the experimental layout and data acquisition scheme, which we hope provides the necessary context.
Author Response File: Author Response.pdf
Reviewer 2 Report
Manuscript ID: sensors-2517566
Title: Nonlinearities in Long-Range Compact Michelson Interferometers
Author: Jiri Smetana, et al.
In this manuscript, the authors summarized and discussed the impact of nonlinear noise in Michelson-type interferometric displacement sensors when placed in high-RMS-displacement applications. On this basis, they further investigated three primary sources of nonlinearity that arise in the sensor—residual ellipticity, intrinsic distortion of the Lissajous figure, and distortion caused by exceeding the velocity limit imposed by the demodulation algorithm. The manuscript is well written and properly organized, however, I do have the following comments to make the manuscript more satisfactory:
(1) In this manuscript, the focus of the abstract section is on the linearity of the device. However, in most chapters of the article, the focus is on the impact of linearity on displacement sensitivity. It is suggested to clarify What the abstract focuses on?
(2) It is recommended that you optimize the introduction section, as well as a summary of the work in Ref. [8].
(3) For Sec. 2.2 , the systematic nonlinear error caused by the remain residual elliptity to the Lissajous figure , maybe can be better explain by drawing a comparative diagram.
(4) For ease of viewing, it is recommended that figure 5 be the same size as figures 4 and 2.
Author Response
We would like to thank the reviewer for their useful comments and suggestions. We have made the following changes based on the constructive criticisms:
(1) We have reworded the abstract to highlight more prominently our focus on the nonlinearities' impact on sensitivity.
(2) We have significantly expanded the introductory section (particularly the background theory), which includes more information about previous work in Ref. 8.
(3) We have added a new figure (Fig. 2), which shows this comparative diagram of the effects of Lissajous ellipticity on the nonlinear error on displacement estimation.
(4) We have resized the figure to match the others as requested.
