Backscattered Background Noise of the Lidar Ceilometer Influence Imposed by ASE in Single-Frequency Nanosecond Pulsed Laser at 1.5 μm

Round 1

Reviewer 1 Report

 

Backscattered background noise of the lidar ceilometer influence imposed by ASE in single-frequency nanosecond pulsed laser at 1.5 μm

 

Authors: Qi Gao, etal

 

The paper discusses a three-stage all-fiber master oscillator power amplifier (MOPA) system designed to generate high-power, linearly polarized, narrow-linewidth pulses at a wavelength of approximately 1.5 μm. The goal is to amplify the output power from the master oscillator to achieve over 1 W of output power. The authors analyze the effect of ASE on the first derivative of backscatter intensity which is a measure of the scattering of light when it interacts with particles or objects in its path, and its derivative can provide valuable information about the environment.

 

In summary, this work involves the development of a high-power, narrow-linewidth laser system and highlights the importance of minimizing ASE noise for applications like cloud detection where precise measurements are required. The authors conduct experiments to understand how ASE affects backscatter intensity and aim to enhance the laser's performance for such applications.

These results are of interest to the research community and may motivate more applications in photonics.

 

When reviewing the nonlinearity, I would suggest the authors a paragraph about the description of Nonlinear optical materials (NLO). NLO play a crucial role in various applications within the field of photonics and optical communication. These materials exhibit nonlinear responses to intense optical fields, enabling a wide range of functionalities and applications. e.g  https://doi.org/10.3390/e23101353 and foresee potential applications with current technology. For example, photonic graphene is a unique and emerging class of nonlinear optical material that has gained attention in recent years for its potential in various photonic and optical applications, including optical modulation, https://doi.org/10.1103/PhysRevB.93.085404 and photonic band gap media are promising to obtain nonMarkovian behaviour and provide a reliable way to transmit entanglement over long distance which is potential application for quantum communication,          Sci Rep 12, 11646 (2022). https://doi.org/10.1038/s41598-022-15865-5.

The manuscript is well generally written but needs substantial improvement by providing a more complete exposure to the field, especially to those pertaining to the wide audience regarding Nonlinear optical materials and photonic bandgap materials and optical phase. With all the following edits and clarifications made satisfactorily, I would recommend this work for publication in Photonics.

 

Author Response

Thank you for your letter with regard to our manuscript entitled “Backscattered background noise of the lidar ceilometer influence imposed by ASE in single-frequency nanosecond pulsed laser at 1.5µm” (Manuscript ID: photonics-2609298) together with the comments from reviewers. We quite appreciate your careful consideration and the reviewers’ insightful comments. Those suggestions are very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have carefully revised the manuscript according to the reviewers’ valuable comments. All changes made to the text are highlighted in red so that they may be easily identified. We believe that the manuscript has been greatly improved and hope it has reached your magazine’s standard.

Once again, we acknowledge your comments very much, which are valuable in improving the quality of our manuscript.

Thank you very much!

Best regards,

Qi Gao

Author Response File: Author Response.pdf

Reviewer 2 Report

The authors report the development and characterization of a nanosecond pulsed laser at 1500nm. The system is based in all-fiber MOPA system. The emission characteristics were an average power of 1W at the pulse repetition of 10kHz and the pulse width of 400ns. It was analyzed the influence of the ASE on the backscatter intensity of the lidar celiometer.

The paper is suitable for publication in Photonics. However some issues must be clearly addressed:

It is not clear, what parameters are necessary to improve regarding the lidar celiometer used for cloud based on fiber laser technology?

Also, it is important to compare the obtained results with the existing systems.

How your results will improved the function characteristics of existing lidar ceilometers?

Author Response

Thank you for your letter with regard to our manuscript entitled “Backscattered background noise of the lidar ceilometer influence imposed by ASE in single-frequency nanosecond pulsed laser at 1.5µm” (Manuscript ID: photonics-2609298) together with the comments from reviewers. We quite appreciate your careful consideration and the reviewers’ insightful comments. Those suggestions are very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have carefully revised the manuscript according to the reviewers’ valuable comments. All changes made to the text are highlighted in red so that they may be easily identified. We believe that the manuscript has been greatly improved and hope it has reached your magazine’s standard.

Once again, we acknowledge your comments very much, which are valuable in improving the quality of our manuscript.

Thank you very much!

Best regards,

Qi Gao

Author Response File: Author Response.pdf

Reviewer 3 Report

Your paper entitled, Backscattered background noise of the lidar ceilometer influence imposed by ASE in single-frequency nanosecond pulsed laser at 1.5μm, is well written. The meteorological and aviation communities can benefit from a lidar ceilometer operating with sufficient laser pulse energy, while maintaining low background noise for cloud detection. Your approach to investigate the effect of amplified spontaneous emission (ASE) on the backscatter intensity of a lidar ceilometer has merit.  Experimental results show that as the ASE power in single frequency pulsed lasers increases, the noise intensity of the first derivative of backscatter intensity increases with angle of the inclination, which decreases the signal-to-noise ratio (SNR) of the output power. Your conclusion is that low background noise can only be achieved when the ASE level is very low in the output signal.

 My comments/recommendations are provided below.

• Reference Lines 66-68. This is not a complete sentence.
• Reference Lines 254-257.  As the ASE power increases, the noise intensity of the first derivative of backscatter intensity increases with an angle of the inclination, which can cause the backscattered signal to be drowned out in the lidar ceilometer. Recommend that the maximum (critical) ASE power, beyond which the backscatter noise cause poor performance of the lidar ceilometer, be provided.

I made several suggestions to improve sentence structure (See the attached PDF document – Comments / Recommendations are in Sticky Notes).

Comments for author File: Comments.pdf

See attached pdf file.

Author Response

Thank you for your letter with regard to our manuscript entitled “Backscattered background noise of the lidar ceilometer influence imposed by ASE in single-frequency nanosecond pulsed laser at 1.5µm” (Manuscript ID: photonics-2609298) together with the comments from reviewers. We quite appreciate your careful consideration and the reviewers’ insightful comments. Those suggestions are very helpful for revising and improving our paper, as well as the important guiding significance to our researches. We have carefully revised the manuscript according to the reviewers’ valuable comments. All changes made to the text are highlighted in red so that they may be easily identified. We believe that the manuscript has been greatly improved and hope it has reached your magazine’s standard.

Once again, we acknowledge your comments very much, which are valuable in improving the quality of our manuscript.

Thank you very much!

Best regards,

Qi Gao

Author Response File: Author Response.pdf

Round 2

Reviewer 2 Report

The authors have taking into account the comments and improved your paper.

In my opinion, the paper is suitable for publication in present form.