Compensation of the Distorted WDM Signals by Symmetric Dispersion Map with Nonuniform Zero-Crossing Place of Accumulated Dispersion in Midway-OPC System
Round 1
Reviewer 1 Report
Dear Authors,
Various symmetrical distribution maps are proposed in the article, where the position of the zero crossing of the cumulative distribution is not fixed. In addition, the effect of each dispersion map configuration on 40 Gbps × 24 channel WDM signal distortion compensation was analyzed. Most of the proposed scatter maps have been verified to be more effective than the traditional scatter map in compensating for the distorted WDM signal. In particular, it has been confirmed that among the proposed dispersion maps, the dispersion map in which the RDPS is designed uniformly for all fiber openings can increase the power margin of the WDM channel and expand the overall residual dispersion range in the scatter-managed link. The article is a numerical and simulation study, and experimental verification of the obtained findings is important. Authors must prove the accuracy of the findings with experimental validation. Today, compensation is made with DCF modules and electronic cards. The novelty of the proposed method should be discussed by the authors in this context. In addition, the following corrections are required.
There are too many keywords. It is sufficient to write "residual dispersion" instead of "residual dispersion per fiber span; total residual dispersion; chromatic dispersion".
Which simulation environment was used in the article should be stated.
What is the length of the DCFs in Figure 1? Parameters such as total link length, input signal information, noise value, BER analysis should be given. Figure 1 should be explained in detail.
How does Part 3 relate to simulations? It should be explained.
Since figures and figure citations are on different pages, the readability and traceability of the article has decreased. All shapes and wastes need to be regulated.
Figure 5 is not understood.
The findings are not clear and understandable. It would be appropriate for the authors to present their article findings and literature findings comparatively.
Minor editing of English language required
Author Response
We are grateful for the elaborate and warm review of our paper. We have reflected and revised the reviewer's comments and recommendations.
If there are things that have not been corrected by fully reflecting your opinion, we have stated our reasons in the attached document, so please understand our situation with a generous heart. One thing I can say for sure is that your comment will be very helpful for our next research.
"Please see the attachment."
Author Response File: 
Author Response.docx
Reviewer 2 Report
In this study, the authors claim to propose a new concept for dispersion maps. Unlike previously proposed methods, the dispersion maps evaluated in this study have a nonuniform structure where the zero-crossing point of the cumulative dispersion is not constant. The aim is to examine the effect of various dispersion maps designed by the authors for distortion compensation of WDM channels so that the cumulative dispersion is zero-crossing only at the 2nd, 4th, 8th, and 16th fiber spans in each half of the transmission link consisting of 30 fiber spans.
I have the following comments regarding the study:
1- The authors have performed a simulation study but have not clarified which tool they have used.
2- The authors have presented the well known NLSE, but have not linked it properly with their work and results. The effects of SPM and dispersion on the eye diagrams should be discussed.
3- The authors say that they have ignored XPM, since the dispersion coefficient is large. While this is partially correct, XPM still has a major contribution depending upon the power of each channel. For 24 channel WDM, XPM cannot be ignored.
4- The performance of the proposed scheme has been analyzed with the help of eye opening penalty (EOP). This is not a very quantitative measure of performance. Instead, the authors should show BER plots on the same figure, so that a clear comparison and performance analysis can be performed.
5- The authors need to compare the BER performance of their proposed maps with the conventional maps to justify their claim that their maps perform better than conventional.
6- There are some sentence mistakes in the paper.
a- In the title: "Nonuniformly Zero-crossing Place" should be nonuniform zero-crossing point etc
b- "great effect" should be significant effect.
c- line-90: has should be have.
d- "which the FSG a given fiber span belongs to"
e- line 456: "can be more increased"
a- In the title: "Nonuniformly Zero-crossing Place" should be nonuniform zero-crossing point etc
b- "great effect" should be significant effect.
c- line-90: has should be have.
d- "which the FSG a given fiber span belongs to"
e- line 456: "can be more increased"
Author Response
We are grateful for the elaborate and warm review of our paper. We have reflected and revised the reviewer's comments and recommendations.
If there are things that have not been corrected by fully reflecting your opinion, we have stated our reasons in the attached document, so please understand our situation with a generous heart. One thing I can say for sure is that your comment will be very helpful for our next research.
"Please see the attachment."
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The authors made the necessary corrections.
Author Response
Thank you again for your generous and thorough comments.
Reviewer 2 Report
The authors have addressed some of my minor comments but they have not addressed the major comments No. 3 and No. 4. The reason they have mentioned is that this will require further time consuming simulations. Honestly, I am not sure if this is a suitable reason because I believe if comment-3 is addressed, the results would be significantly different.
Based on the above reason, I leave it to the editors if they would like to accept or reject the paper.
Author Response
I respect your judgment and thank you again for your efforts.
"Please see the attachment."
Author Response File: Author Response.docx
