Design of Control Circuit for Tunable Semiconductor Laser for Fiber Sensing

Round 1

Reviewer 1 Report

This was a well written paper and the background, goals, and findings of the study were clearly laid out.  There are several changes that should be addressed before this paper is published.

First, several figures (Fig. 3 and Fig. 15) have non-English characters (presumably Chinese).  At a minimum, the translation of these characters to English should be provider in the figures.

In Table 1, the word thermistor is mis-spelled.

I would also like for the authors to address two characteristics of their data as presented in Table 3 and Figure 17.  First, there is a small offset between the set wavelength and the actual wavelength that is recorded.  The manuscript should offer an explanation for why this offset occurs and what (if anything) can be done to minimize it.  Second, some of the set wavelengths (e.g., 1525.382, 1528.555, 1533.748, and 1548.65) appear to show a small (< 3 pm) decrease over the measurement interval (20 minutes) whereas the readings from the other two set points are more random.  The manuscript should address this trend and preferably should address what would happen over a long period (e.g., > 1 hr or when it comes to homeostasis ) to the laser emission wavelength.  This information would be helpful to the user to decide whether this approach is acceptable for their application.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Dear Authors,

Your work on the design of a tunable laser control circuit based on the STM32 microcontroller is commendable. However, there are some key points that require further clarification. Firstly, it's essential to provide citations for any circuit diagrams that might have been adapted or sourced externally. Additionally, offering more in-depth insight into the selection criteria for the integrated circuits, performance evaluation methodologies, and the practical implications of the achieved stability and wavelength range would significantly enhance the paper's value.

Please consider providing more comprehensive explanations for the integrated circuit selection process, the significance of the achieved wavelength range, and the practical implications of the attained stability. Further detailing the performance evaluation methods and limitations encountered during the experimentation phase would strengthen the paper's technical credibility.

1.       Could you specify the sources or origins of the circuit diagrams used in this study? It's crucial to provide appropriate citations, especially for diagrams that have been adopted or adapted from other sources.

2.       The integration of specific chips (MAX5113, MAX1978, AD7798, HA1004, etc.) is mentioned. Could you further explain the selection criteria for these chips in the context of the design objectives and performance requirements?

3.       Are there any specific reasons or features that led to the selection of these particular integrated circuits? For instance, considerations such as precision, power consumption, integration capabilities, or any comparative analyses might be helpful.

4.       In the experimentation phase, how were the performance metrics defined and measured for each module?

5.       Were there any limitations encountered during the performance evaluation of these modules?

6.       The conclusions highlight the precise wavelength output and stability achieved. Could you further elaborate on the significance of the 1525 to 1550 nm range and the implications of the 3 pm maximum fluctuation rate in practical applications?

7.       The integration of MAX5113 and MAX1978 is emphasized for precise control. Could you discuss the influence and impact of these specific chips on the overall laser control system's performance?

8.       The discussion mentions the consideration of these modules for demodulation. Could you elaborate on their roles in ensuring wavelength stability and system reliability?

9.       Is there a discussion or plan for potential improvements or modifications in the future based on the findings of this study? For instance, enhancing the system for broader wavelength ranges or specific applications.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

Dear authors,

Thank you for addressing the feedback.