Integrated Components and Solutions for High-Speed Short-Reach Data Transmission

Round 1

Reviewer 1 Report

Please see the attached file.

Comments for author File: Comments.pdf

Author Response

 Thanks for your very meaningful suggestions. Please see the attachment. 

Author Response File: Author Response.docx

Reviewer 2 Report

The authors aim to review different transmission technologies with an aim to focus on the short-to-medium distance. The authors did a thorough literature study and the references are up to date and recent.

Unfortunately, the review-part is where this paper falls short. Technologies and several papers with the corresponding parameters, e.g., transmission rate and distance, are plainly listed in text. The closest to a proper comparison of the different approaches is found in Figure 16 and Part 5. The Figure is not intuitive enough to be understood without a proper caption. E.g., the arrow for the "Cost, Power consumption" is apparently representing a decrease instead of an increase. Overall this section should be expanded as it stands to be the main body of work. The factor "cost" should be explored more, as it is not clear to me what is considered part of it. In its current presentation, cost and power consumption are strongly related; so much that they are identical when placed on an axis of a Figure.

On top of that, several figures are unreadable. Examples are Figure 12, 13, and 15, among others. The articles uses a lot of reprints from other publications (that is of course normal for review papers) and the copyright of those figures is not yet mentioned properly.

Section 4.1 with mathematical derivations might be out of place for a review paper.

I think the manuscript needs a restructuring and a focus on what the title of the article promises to deliver. After reading the article I still have no idea what the cost of a transmission system would be, e.g. in dollar per bit or similar, or what kind of power consumption I can expect. In my eyes, only the literature search part of the review work has been done, or at least been presented, and significant changes are required before this can be called a review. I encourage the authors to re-submit the article at a later stage.

Author Response

 Thanks for your very meaningful suggestions. Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

The authors have addressed my prvious comments and concerns. I believe the paper is suitable for publications. The field is evolving extremely fast and this review helps newcomers to catch up. Thank you for the tramendous work in preparing such a good review. 

Author Response

We would like to thank the reviewer for the constructive comments that helped us to improve the quality of our manuscript. 

Reviewer 2 Report

The authors did substantial improvements regarding the review part. Tables have been included that compare bandwidth, data rate, and other important quantities.

Unfortunately, the article still falls short on a few points:

The figures are still unreadable. In Figure 1, the inset of (b) is too small and too low resolution, the different colors are not explained. In general, the captions should explain the acronyms and symbols used in the figure; at least the non-trivial ones. Figure 3 (b) contains markers for a and b, without mentioning what they refer to. Figure 4, especially part (c), is of low resolution and potentially not even useful for this work. The authors also chose to numerate abcdf; skipping e. Unusual, but acceptable if that was the intention. Figure 6 is strictly speaking meaningless, as none of the symbols have been explained. Either the reader knows in advance what is shown, or the figure will not help to get an understanding. In both cases the figure would be redundant. Figure 7 suffers from the same problem. I will stop going through the list here.

The quantity "cost" has still not been explained. This is unfortunate as at least by title this is a focus point of the review paper. Is it the cost per device? The cost per Gbit/s? The cost per km? And what kind of ball park figure are we talking about?

DML has been defined twice in the manuscript (line 50, p.2) and as section 2.2 heading (page 4); in both cases with a different meaning, and in both cases deviating from the standard definition (directly modulated laser).

There are several phrasing issues, such that I recommend giving the manuscript another read-over. A lot of the statements are "well-known"; I counted six usages of that phrase. I would avoid that phrasing, but that is matter of style.

The article improvements have been substantial, such that I updated my recommendation to publish the article after major revisions.

 

Author Response

We would like to thank the reviewer for the constructive comments that helped us to improve the quality of our manuscript. Please see the attachment.

Author Response File: Author Response.docx

Round 3

Reviewer 2 Report

The authors did substantial improvements on most of the points. The term "cost" is now defined as the cost per component; which is not the worst definition to use (although e.g. cost per bandwidth could have merits). In any case, title and abstract are not formulated as to make this the major focus point of the manuscript anymore.

The authors improved many of the figures. However, since Figure 1(b), especially on the in-set, contains unreadable font, I have to assume at this stage that this is either a problem of my PDF-reader or an compression artifact from the publisher. I have discussed this point enough, and leave the decision, whether the quality of the figures (e.g. Figures 1, 2, 3, 4, 7, 10, 11...) is sufficient, to the editor.

In consequence, I classify the manuscript as publishable after minor revisions, which should mainly be the improvements of the Figures.