Optimization of Erbium-Doped Fiber to Improve Temperature Stability and Efficiency of ASE Sources

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

1. The functions of the filter and reflector are respectively to reflect the signal light back to the EDF for re-amplification. However, there is no explanation provided in the article. If the structure can amplify the power, why do we need to optimize the EDF.

2. “The inorganic metal chloride vapor phase doping method combined with the modified chemical vapor deposition process was used to manufacture EDFs”, Please provide a production process.

3. The paper is not concise enough, and attention should also be paid to English grammar.

4. Has the optic gyroscopes (FOGs) production been completed? We cannot establish a close connection with this paper.

5. In Figure 8, What is the basis for selection different length of EDF. Please give a detailed explanation.

6. Please provide a detailed comparison with other research findings regarding optimize EDF.

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 2 Report

Comments and Suggestions for Authors

A very nice work!

The results are importante and must be publicated.

Just one minor detail before publication - line 269, replace “shave” by “have”

Author Response

Please see the attachment. 

Author Response File: Author Response.pdf

Reviewer 3 Report

Comments and Suggestions for Authors

The authors have provided an interesting and timely work with an important practical component. The stability of fiber-based radiation sources is the key to the successful operation of various optoelectronic devices, including fiber optic sensor interrogation systems. However, I would like to ask the authors to pay attention to some of my comments. I consider it appropriate to publish this article after the shortcomings have been corrected. My comments on this article are given below:

1. Not as a requirement, but as a wish: maybe there are fiber refractive index profiles?

2. Due to the fact that the chemical vapor deposition from the gas phase (MCVD) method is quite difficult to control, the statement that two fibers have the same concentration of erbium oxide seems strange. How was this concentration estimated? By luminescence intensity? Or solely by process parameters? If so, is clustering taken into account?

3. Why were these three types of fiber chosen for modeling? This is already briefly described in the text, but it would be great if the authors explained these reasons in more detail. Does the simulation allow modeling even more stable fiber structures than EDF1-3? Does the experiment indicate the adequacy of the model? These things should be clearly written in the conclusion.

4. On what basis is it judged that the doping components are uniformly distributed along the fiber? I know the only way to check this without destroying the samples, and this approach is described in [http://dx.doi.org/10.3390/opt5010013]. Has any similar approach been used?

5. How stable is the pump diode in wavelength, mode composition and radiation intensity?

6. Figure 3 is located at the end of the section, I would suggest moving it higher, right after the first mention.

7. The pump diode, like the active fiber, is part of the FOG optical scheme. Therefore, harsh environmental conditions can affect it as well. Is a thermal test of the entire ASE planned?

8. In the reference [5], the last name of the co-author is misspelled: the last letter is replaced by an affiliation number.

9. Please check the units of measurement in Table 1. Are you sure that the core diameter and other similar-sized objects can be so huge?

10. Length and concentration determine, as I understand it, two parameters: temperature stability and efficiency. So, optimal efficiency does not always equal maximum stability, right? If so, some method for finding a compromise should be developed in the future. Maybe this should be mentioned as a future work?

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Reviewer 4 Report

Comments and Suggestions for Authors

The manuscript presents a thorough investigation into optimizing erbium-doped fiber (EDF) to improve the temperature stability and efficiency of amplified spontaneous emission (ASE) sources, which are critical for fiber optic gyroscopes (FOGs). The authors use both simulation and experimental methods to demonstrate significant improvements. The content is clear, well-organized, and contributes valuable insights to the field. However, a few minor revisions are recommended to improve clarity, presentation, and the technical rigor of the manuscript. After addressing these comments, the manuscript will be well-positioned for publication.

1. The description of the ASE source performance evaluation (Section III) could benefit from more precise details regarding the environmental conditions, such as how long the system was allowed to stabilize at each temperature point. This would help ensure reproducibility of the experiments.
2. The paper uses both ppm/°C and percentage change rates when describing temperature stability and power conversion efficiency. A unified presentation of these metrics (either all in ppm or percentage) would improve readability and make comparisons between different EDFs clearer.
3. In “Table II and Table III”, performance metrics (e.g., “Mean wavelength shift”, “Power conversion efficiency”) are listed for ASE sources utilizing different EDFs. It would be helpful to include statistical metrics (such as standard deviations or ranges) for these parameters where applicable to provide more quantitative insight into the reliability and reproducibility of the results. This is particularly relevant for industrial applications, where consistent performance is critical.
4. Figures, such as Fig. 2, Fig. 3, and Fig. 4, are crucial to demonstrating temperature-dependent variations in the ASE source performance. However, the resolution of some of these figures should be improved, and it would be helpful to provide more detailed captions.

Comments on the Quality of English Language

none

Author Response

Please see the attachment.

Author Response File: Author Response.pdf

Round 2

Reviewer 1 Report

Comments and Suggestions for Authors

The abstract repeatedly mentions fiber optic gyroscopes, but the focus of this article is on optimizing ASE. Suggest revising the abstract to highlight the key research content ASE of this article.

Author Response

Comments to the Author

The abstract repeatedly mentions fiber optic gyroscopes, but the focus of this article is on optimizing ASE. Suggest revising the abstract to highlight the key research content ASE of this article.

Reply : Thank you for the constructive comments. We have revised the abstract based on your suggestion, removing the mention of fiber optic gyroscopes and instead focusing on the study of the ASE light source itself.