In-Loco Optical Spectroscopy through a Multiple Digital Lock-In on a Linear Charge-Coupled Device (CCD) Array
Round 1
Reviewer 1 Report
In this manuscript, the authors propose a new technique based on digital lock-in processing that enables the use of CCD spectrometers in optical spectroscopy applications. The effectiveness of their method is confirmed by testing and recovering the spectrum of a yellow LED subjected to other light sources in outdoor conditions. This research could be a significant contribution to the field and can be helpful to the community working in this field. The manuscript is well written and presented appropriately. Overall, I can recommend the publication of the manuscript. However, the authors should answer some questions:
1.The curve in Figure 2 is too thin, while the curves in Figures 5-7 are too thick.
2. Please explain the origin of formulas (5) and (6)。
3. Is the outdoor testing time long enough? Figure 8 shows only 15 minutes.
Author Response
Dear Reviewer:
We thank you very much for your appreciation of our manuscript with your comments and observations. Each of your comments were answered in the best possible way. Attached is a .pdf with the answers.
To better clarify part of your questions, it was necessary to make changes to the manuscript. It would be important to send you the new version of the manuscript. I am waiting for this request.
Yours sincerely,
Dr. Ricardo Ataide de Lima.
Author Response File: 
Author Response.pdf
Reviewer 2 Report
1.Try not to include possible or uncertain vocabulary in the abstract, so the "may" in line 11 needs to be removed.
2.This paragraph has no subject in line 56:"In the following section is described the lock-in process". in line 59-60:"In the third section are described the optical experiments"
3. In line 128, what is the relationship between n and N, are thet same or not. Please make it clear.
4. Can you explain the purpose of using light-emitting diodes of different colors in the experiment.
5.Figure 5, Figure 6, and Figure7, Please give out the physical dimensions of horizontal and vertical coordinates.
6.There are many waveforms and curves describing the results in this article, but the explanation of the principle of Lock-in is insufficient.
The grammar needs further modification
Author Response
Dear Reviewer:
We thank you very much for your appreciation of our manuscript with your comments and observations. Each of your comments were answered in the best possible way. Attached is a .pdf with the answers.
To better clarify part of your questions, it was necessary to make changes to the manuscript. It would be important to send you the new version of the manuscript. I am waiting for this request.
Yours sincerely,
Dr. Ricardo Ataide de Lima.
Author Response File: Author Response.pdf
Reviewer 3 Report
General Comments:
The paper titled "In-loco optical spectroscopy through a multiple digital lock-in on a linear Charge-Coupled Device (CCD) array" presents an interesting and innovative approach to optical spectroscopy using a multiple digital lock-in technique on a linear CCD array. The authors have provided a well-written and clear manuscript with comprehensive theoretical and experimental analyses. The validation experiments are well conducted and effectively highlight the benefits of the proposed technique. I am pleased to note that the experimental setup used to validate the proposed technique is well described, and all the relevant parameters are reported with sufficient clarity and accuracy. The work showcases the potential for significant advancements in spectroscopic techniques, and it addresses an important problem in the field of optical sensing.
Comments:
Comparative Analysis: While the validation experiments demonstrate the enhancement of sensitivity achieved by the proposed multiple digital lock-in technique, it is not clear from the introduction if other techniques for in-situ spectroscopy provide similar improvements in sensitivity. Including a comparison of the proposed technique's sensitivity enhancement with existing methods in the introduction would provide valuable context and emphasize the novelty of the approach.
Discussion of limitations: Although the results are promising, the paper would benefit from a clear discussion of the limitations of the proposed method. The authors should address potential challenges and constraints that might arise in practical implementations and suggest possible solutions or improvements to mitigate these issues.
The authors could provide a more detailed explanation of the calibration procedure for the CCD array and how they account for potential non-linearities in the response.
Captions of figures 5, 6 (pag 6 and 7) refer to less subplots than actually present in the plots: fig 5 caption refers to subplots a), b), and c) and forgets about plot d); fig 6 caption refers to a) and b), and fogets about c).
Page 10, figure 8 c): the y-scale could be zoomed-in, so to allow an easier appreciation of the variations in the reported correlation parameter.
Overall, the paper presents a novel and promising technique for optical spectroscopy. The manuscript is well-written, and the experiments are conducted with attention to detail. The validation experiments effectively demonstrate the benefit of the proposed technique in enhancing sensitivity. However, it would be beneficial to include a comparative analysis with other in-situ spectroscopic methods to highlight the uniqueness of the approach. I commend the authors for providing a well-described experimental setup and reporting all relevant parameters with clarity and accuracy. The work will undoubtedly be of significant interest to the scientific community. However, I recommend the authors address the concerns mentioned above before considering the paper for publication.
Author Response
Dear Reviewer:
We thank you very much for your appreciation of our manuscript with your comments and observations. Each of your comments were answered in the best possible way. Attached is a .pdf with the answers.
To better clarify part of your questions, it was necessary to make changes to the manuscript. It would be important to send you the new version of the manuscript. I am waiting for this request.
Yours sincerely,
Dr. Ricardo Ataide de Lima.
Author Response File: Author Response.pdf
Round 2
Reviewer 2 Report
1.When the parameter α is determined, Equation 3 and Equation 6, Equation 4 and Equation 7 should correspond, what is the meaning of parameter τ in Equation 4 and 7
2.In the experiment, the author used 589nm yellow light, whether to consider adding other wavelengths of light for verification.
Note capitalization of proper nouns
Author Response
Dear Reviewer:
We thank you very much for your appreciation of our manuscript with your comments and observations. Each of your comments were answered in the best possible way. Attached is a .pdf with the answers.
Author Response File: Author Response.pdf
