FMCW Laser Ranging System Based on SiON Waveguides and IQ Demodulation Technology
, Xiao Ma 2, Ting Chen 3,* and Lei Wang 4
Round 1
Reviewer 1 Report
Comments and Suggestions for AuthorsComments for author File: 
Comments.pdf
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
Comments and Suggestions for AuthorsThis manuscript presents a study on nonlinear FMCW laser ranging systems. The frequency information of the nonlinear FMCW signal is obtained by using an on-chip interferometer based on SiON waveguides and IQ demodulation technology.The results in this manuscript are complete and convincing. Hence, this manuscript can be accepted for publication in MDPI Photonics after addressing the following issues.
(1) The width of the window function in the FFT calculation has not been given. In addition, the time consumption in the measurement should be presented.
(2) How about the measurement stability in a long duration? The authors only exhibit the experiment results in 50 times testing. Is there any measurement result in a long duration?
(3) There is a spurious signal in Fig. 10 at about 12 m with an amplitude of about 65 dB. The authors should explain why this spur appears.
(4) The clarity of Fig. 13 is insufficient and the original image needs to be presented.
Comments on the Quality of English LanguageThe English expression should be further improved.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Comments and Suggestions for AuthorsIn the manuscript titled FMCW Laser Ranging System Based on SiON Waveguides and IQ Demodulation Technology, the authors performed a nonlinear FMCW laser ranging system based on IQ Demodulation Technology and optimized resampling algorithm. The results have some novelties in improving ranging performance than the traditional HT algorithm. However, there exists many issues, and meanwhile the relevant description is unclear. Therefore, I think this manuscript cannot be accepted for publication in PHOTONICS.
Comments:
#1. The detailed expressions of phase Ï•1 and Ï•2 should be given in the equations 5 and 6.
#2. The full names of some acronyms in the text are not given. For example, the PCHIP in line 113.
#3. The names of each device in Figure 2 are inconsistent with the text, such as the Coupler and the beam splitter, the On-chip interferometer, and the IQ demodulation chip, if they are the same one, please unify the description.
#4. In line 152, the authors declare that the four output ports have mixing phases of 0, 90, 180, and 270 degrees, which is not consistent with the Fig. 3(a).
#5. The simulation results in Fig. 5 are used to design which part of this experiment, the author should clarify accordingly.
#6. The RBW and VBW values should be clarified in the FFT spectrum.
#7. There are many grammatical errors in the manuscript.
Comments on the Quality of English LanguageThere are many grammatical mistakes in the manuscript.
Author Response
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Author Response File: Author Response.pdf
Round 2
Reviewer 3 Report
Comments and Suggestions for AuthorsAccroding to the suggestion, the authors complete the corresponding modification. I think it can be accepted in present form.
