A CMOS Double-Demodulation Lock-In Amplifier for Stimulated Raman Scattering Signal Detection
, Keita Yasutomi 2, Keiichiro Kagawa 2, Mamoru Hashimoto 3 and Shoji Kawahito 2,*
Arjuna Marzuki
Round 1
Reviewer 1 Report
The authors developed a solid-state SRS detector using a CMOS Double-Demodulation Lock-in Amplifier, and the effectiveness of the chip prototype has been demonstrated. They proposed a two-stage amplification circuit for Double-Demodulation operation to suppress the 1/f noise, and achieve a low noise system for SRS detection. Their preliminary results suggest that the SRS chip can effectively suppress low-frequency noise components and improve the SRS signal resolution.
The presentation is well organized, the method developed is interesting and of practice significance. I recommend the paper to be published in the Electronics.
Author Response
Point 1: The presentation is well organized, the method developed is interesting and of practice significance. I recommend the paper to be published in the Electronics.
Response 1: Thank you very much for your comments. We highly appreciated it.
Reviewer 2 Report
It is better to compare with similar works—especially the efficacy and efficiency of the design. Eg. PVT results.
It is also advisable to discuss more details of the CMOS circuits. Eg. In Fig 10c. What is the pixel? is it the photo-demodulator? At Fig6a. Is A1 the same as A2?
Author Response
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Author Response.pdf
Reviewer 3 Report
Dear Editor,
The manuscript “A CMOS Double-Demodulation Lock-in Amplifier for Stimulated Raman Scattering Signal Detection” by Shukri Bin Korakkottil Kunhi Mohd and co-authors describes their work of a complementary metal-oxide semiconductor (CMOS) image sensor for stimulated Raman scattering (SRS) signal detection. The sensor uses double-demodulation lock-in scheme to perform signal offset subtraction and 1/f noise removal. This seems like a full integrated circuit solution of the co-authors’ work in 2016, see ref. [15] of the manuscript. Although the key components of the current work are reported in other references, the integrated sensor can significantly simplify the SRS detection electronics, thus can generate potential interest for the SRS community.
The current manuscript needs to be improved for some aspects to enhance the readability. Some major comments are:
1. The abstract and introduction part of the manuscript state 40 MHz operation frequency, but the main text later says 20 MHz, please clarify.
2. The introduction paragraph on SRS does not cite some important early works of this field in literature.
3. In introduction: How does the performance of the device compare to the state-of-the-art measurements?
4. Fig. 4: To complete the description of the demodulator, adding a Y-Y’ cross-section would be helpful, as well as explain why using three-step doping instead of two, and what are the doping densities? The potential scale is missing from 4(b).
5. Fig. 5(b): Color scheme scale is missing, what are the colors? Are they electric field strength?
6. Fig. 6: (a) Is Ø5 missing from diagram? (b) Maybe the diagram is misleading, but it seems that half of the signal is lost during the first stage charge integration, is it right?
7. Fig. 9: What are the limiting factors for non-linear response below 10E-6?
Some typo that needs attention:
1. Please spell out all acronyms when they first appear in the MAIN text.
2. It would be better to specify at least frequency range of fm1 and fm2 in section 2 to reduce confusion.
3. Line 166: the sentence does not make sense.
4. Line 243: a red “.”
Based on the above observations, I recommend a revision of the manuscript before publication.
Referee
Author Response
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