Hybrid Silicon Nitride Photonic Integrated Circuits Covered by Single-Walled Carbon Nanotube Films
, Pavel An 2,3, Vadim Kovalyuk 1,2, Alexander Golikov 2,4, Yury Gladush 5, Aram Mkrtchyan 5, Dmitry Chermoshentsev 5,6, Dmitry Krasnikov 5, Albert Nasibulin 5 and Gregory Goltsman 1,6,*Round 1
Reviewer 1 Report
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Comments for author File: 
Comments.pdf
The quality of English is acceptable.
Author Response
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Author Response File: Author Response.pdf
Reviewer 2 Report
In this manuscript, the authors report the synthesis and integration of single-walled carbon nanotubes (SWCNTs) to silicon nitride (SiN) photonics for characterizing CNT properties and demonstrating integrated thermal-optic modulation, photodetectors, and nonlinear applications.
The manuscript is in general comprehensive with details about device fabrication and measurement. However, the following technical comments should be properly addressed before publication.
1. As mentioned in introduction, 2D materials-based integration to photonic waveguides have already been demonstrated using graphene and other 2D van der Waals materials. The authors should further benchmark with prior similar publications (such as Refs. 8-12, Ref: IEEE Photonics Journal 10, 6600217, 2018) to further highlight the novelty of this manuscript.
Also, the advantages of SWCNT compared to pure silicon nitride is mentioned. Nevertheless, I suggest the authors to briefly comment on their motivation of using SWCNT (in terms of device performance and handiness of material preparations) instead of graphene or 2D transition metal dichalcogenides (TMDs), which were prior mainstream of developing integrated optical modulators and photodetectors respectively.
2. Independent characterization results such as SEM or AFM of the SWCNT (on bare substrate instead of photonic structures) could be optionally supplemented for verifying the quality of the CNTs.
3. Several important references on integrated 2D photonics (Ref: Nature Photonics,10, 227–238, 2016. DOI: 10.1038/nphoton.2016.15), and photonic integration of functional van der Waals materials (Ref: Nature Reviews Materials, 8, 498–517, 2023. DOI: 10.1038/s41578-023-00558-w ) should be added to revised manuscript when mentioning 2D materials.
4. How is the CNTs modelled when using COMSOL simulation? Are they modelled by the effective refractive index in the calculation?
5. I acknowledge the reasonable 1-step aerosol CVD synthesis method mentioned by the authors as an advantage of the proposed research.
It would be interesting if the authors can briefly comment on some potential transfer-free CVD method (such as Ref: Nature 614, 88–94, 2023) that may fundamentally circumvent any transfer-induced defects or residues and is more compatible with foundry mass-production processes.
6. Minor comments.
(1) Ring resonator or micro-ring resonators are typically referred instead of O-ring resonator.
(2) How would be the quality factor Q of the fabricated ring resonators without CNT?
(3) The front of the insets of Fig. 5b is too small.
(4) In terms of writing, typically results, discussions, and conclusions could be presented first. Details on device fabrication of the SiN waveguides etc. could be manifested lastly as methods section.
English is overall okay, while experimental details on device fabrications can be optionally re-organized to the Methods section that appears near the end of paper.
Author Response
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Author Response File: Author Response.pdf
Reviewer 3 Report
Dear Authors, I attached a file with some suggestions
Comments for author File: Comments.pdf
Dear Authors, I attached a file with some suggestions
Author Response
Please see the attachment
Author Response File: Author Response.pdf
