Review Reports

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

The paper deals with manufacturing and experimental results of a 1130nm VCSEL.

The paper is interesting but must address the following points before worth publishind.

1)    In applications were single mode is a desired feature, also polarization is of much concern. In the paper nothing is stated about polarization. This must be mandatorily addressed in the revised paper.
2)     Related to 1):  I find strange the spectrum you show, quite broadened. That might be due to the resolution of your OSA? What is certainly not acceptable is that you declare a RMS spectral with of 0.13 and 0.2 nm for a SINGLE MODE VCSEL.  A single mode VCSEL should have a spectral with equal to its linewidth, i.e. in the GHz range. This must be addressed too.
3)     p. 5, line 139. You say that a 3um VCSEL features a 1.11 mW power, but in Fig. 4 I read 0.4mW. 1.11 revers to the 5um case
4)     Fig. 5 does not fit with Fig.4. In fact I cannot see any clear change in slope efficiency in those curves, but just a change in the power rollower So the sudden jump from 0.2 to 0.45 does not seem correct. Please double check this, comment, and explain.  If such a jump is real, why I cannot see it in Fig. 4. In case, place an inset and zoom the range 0-1 mA and 0-0.5mW
5)     I'm not so happy with Sec.4. The small signal modulation results are really poor. We all know that the dynamical equations depends on lots of paramenters, which you, by the way, do not even provide. Moreover, those applies somehow decently on single mode VCSELs, while you are showing a 7um case, where probably the operation is multi mode. In any case, your rimulations add no value to the paper. I strongly suggest to present the experimental results, possibly at currents more far apart, like 3 and 6mA. Additionally, the effect of size would be interesting. So you might show the performance of the "single mode" case, i.e. 3mA.
6)    The frequency scale in Fig. 7 is not acceptable. When small signal is concerned, one uses GHz. In your case you device is very slow, so you could show a window in linear scale, between 0.1 and 20 GHz, for example.

Comments on the Quality of English Language

English must be improved. There are typos and mistakes.

Author Response

We gratefully appreciate for your valuable comments. We have responsed to your comments point-by-point in coverletter. Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

Within the paper An InGaAs VCSEL Emitting in 1130 nm for Silicon Photonics  Application authors presented their results related with MOCVD growth of IR VCSEL device. The paper deals with very interesting topic of silicon - III-V integrations for photonic circuits. Below I listed my detailed remarks:

1. L 10 - missing space between wells and acronyms in brackets (QWs), the same in L 15, L 62,  L86 and more

2. Missing space between number and unit: L 2, 12, 13, 15, 20 and many more

3. The symbol for Watt is W instead of w, L15

4. L27 - I would use full name of exa instead of E

5. the acronym of VCSEL was explained in the abstract

6. Section 2. VCSEL Design and Fabrication  - what kind of reactor was used, what carrier gas was employed, what MO and dopant sources were used, what temperature and pressure range during the growth were applied? There is a lot of missing information related with structure growth

7. What is a QW/Barrier thickness, what is a In content in the QW?

8. What is the reflectivity of 46 pair n-DBR?

9. Please provide more information about ICP etching, what gases were used to form the plasma, what was the applied power?

10. L88-89: The oxidation depth is precisely controlled during the wet oxidation  process. - How authors precisely controlled the depth of oxidation during the process?

11. Please define the oxide aperture, is it a length of oxidized AlAs or the length of unoxidized material?

12. Figure 2 - why the temperature changes are not constant?

13. Please rotate the right Y axis legend by 180 degree - Fig. 2, 3, 4, 5,

14. Ohm law in line 126

15 Figure 5- why the results for 7 um aperture are not presented in this graph?

16. L150 - incorrect reference to Figure 5 instead of Figure 6

17. L 166 - the citation is a part of the sentence

18. L172 packaged instead of package

 

In general I got the impression that in one part of the paper 7 um aperture laser results are presented and discussed while in other part the results for 7 um laser are omitted, why?

In my opinion paper has to be revised.

 

Author Response

We gratefully appreciate for your valuable comments. We have responsed to your comments point-by-point in coverletter. Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

Thank you for your careful reply.

I would just change the title.

Please substitute "in" by "at"  1130 nm.

Comments on the Quality of English Language

It is understadable, that's OK

Author Response

Thanks for your rigorous comment. I have revised the manuscript's title and applied for the editor to revise the title of the article. Thanks again for your comment.

Reviewer 2 Report

Comments and Suggestions for Authors

Authors added information that In content in QW is 0.38% it means that QW are made of In0.0038Ga0.9962As. Are authors sure about that?

Did you mean In0.38Ga0.62As?

Author Response

Thank you for your comments, i'm sorry for my mistake. This sentence means The In content is 38 %. We use In0.38Ga0.62As QWs in the active region. I have revised the corresponding part in the manuscript. Thanks for your comments again.