Designing a Long Optical Path Direct-Injection-Integrated Cavity for Laser Absorption Spectroscopy

Round 1

Reviewer 1 Report

Comments and Suggestions for Authors

In this paper, a long-path direct injection cavity based on laser absorption spectroscopy is designed, which is meaningful for trace detection. I can consider the publication with the following improvement.

Firstly, it is recommended that the authors perform gas experiments to further compare and verify the optical pathlength. Secondly, it is suggested that the authors add the physical diagram of the system to increase the credibility.

Comments on the Quality of English Language

Minor editing of English language required

Author Response

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Reviewer 2 Report

Comments and Suggestions for Authors

The manuscript photonics-2734499 entitled "Design of Long Optical Path Direct-Injection Integrated Cavity 2 for Laser Absorption Spectroscopy" is well written by the authors. The manuscript is befitting one to accept. Hence I recommend the article to  accept. Accept the manuscript as it is or in the present form.

Author Response

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Reviewer 3 Report

Comments and Suggestions for Authors

In this manuscript, the authors proposed a direct-injection integrated cavity design to address the problem that traditional gas absorption cells cannot achieve both long absorption optical paths and high signal strength. Using traversal and random walk algorithms, the authors obtained a series of designs with a loss rate below 0.4%. Additionally, the authors conducted a stability analysis of this scheme with respect to the structure parameters. They also compare the performance of the proposed scheme with the off-axis integrated cavity method and multi-pass cell method. Overall, the manuscript is well-written and offers a comprehensive description of the methodology and results. I would recommend it for publication with some minor revisions. The following comments are provided for the authors' consideration to enhance the clarity and completeness of the manuscript:

 

(1) Please clarify the structure parameters used in Figure 3 and Figure 7.

 

(2) On page 6, the authors mentioned that ‘Under certain conditions, as the stability condition of the cavity is met, all light rays in this cavity will not escape from the side of the cavity.’ Is the result in Figure 3 in a stable condition, or not?
It would be more helpful to show a comparison between stable and unstable conditions, rather than to show so many cases with different n values. 

 

(3) In Figure 7, ‘Labs’ and ‘Ilost’ should be revised in the correct formation.

Author Response

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