Arbitrary Time Shaping of Broadband Low-Coherence Light Based on Optical Parametric Amplification
Zheng Gong
Round 1
Reviewer 1 Report (Previous Reviewer 3)
The work entitled “Arbitrary time shaping of broadband low coherence light based on optical parametric amplification” contains simulations and experiments.
The following issues should be clarified or should be better done:
- The theoretical part is not seriously presented. In eq. (8) epsilon^(1) is treated as a vector, whil it was a scalar before. Delta k, k_p, k_s and k_i are vectors a not scalars. Most magnitudes are not defined, rho, d_eff etc.
The coupled equations (9) employ i and j for the imaginary unit number.
This theoretical paragraph should be seriously revised. It is better if they give a reference to check that the coupled equations are correct. Also, this set of equations is derived for coherent fields. Why are they applicable to incoherent fields? More details should be given.
- Line 181 Signal-to-noise ratio is a sentence which is isolated
- Figures 1, 4, 5, 6, 8, 9 have low quality.
- Figure 2 has an incorrect x-axis. Shouldn’t it be width in nanoseconds?
- Figure 10, why are there values of intensity below the background?
- The authors should make their presentation in a uniform way. Sometimes they use ns, sometimes 10^-9 s
- The acknowledgement section is for another type of concepts.
- In the abstract and in line 277, the authors claim that the contrast ratio exceeds 300:1. They should compare their results with those obtained by other authors.
None
Author Response
Dear Reviewer:
Thank you for giving us an opportunity to revise our manuscript, we appreciate editor and reviewers very much for your positive and constructive comments and suggestions on our manuscript entitled "Arbitrary time shaping of broadband low coherence light based on optical parametric amplification " (2308244). We have studied the comments carefully and have made revision in this paper. We have studied the comments carefully and have made revision in this paper. The responses to the comments from your reviewers are offered separately, and the main corrections in the paper and the responds to the reviewers' comments are as follows.
Author Response File: 
Author Response.docx
Reviewer 2 Report (Previous Reviewer 2)
The authors have addressed the comments raised in my first review. The paper is suitable for publication.
Author Response
Dear reviewer, thank you for your professional review work on this article.
Reviewer 3 Report (New Reviewer)
The article proposes the use of OPA in a arbitrary time-shaping scheme, leading to improved bandwidth, higher contrast and fast-rising edges.
Despite the incorporation of OPA stages for contrast improvement in high energy lasers being well-known, the use of the technique for improving low coherence light sources for inercial confinement fusion instability suppression is to my knowledge a novelty.
The manuscript itself however is at odds in terms of quality with the research it describes.
A discussion of issues/comments by section is given below:
While the introduction is properly written, the principle and scheme section after its first paragraph is a general mathematical deduction to the OPA coupled equations (which is found in any nonlinear optics book for decades), while the scheme itself is not only not described but also illustrated by a far too simple and poor graphical quality figure.
As a side note, only half of the figures are referenced in the text (although they are placed near their relevance location). Furthermore, with the exception of Figure 7, all figures have rather bad quality, with Figs 1, 5 and 6 not being suitable for publication.
Section 3.1 - While numerical verification is welcomed, there is no comment that all the good properties witnessed are expected and up to a point know by the laser community as a direct consequence of the nonlinearity of the process. This section should be styled more as a confirmation rather than presenting groundbreaking data.
Section 3.2 - There should be added information on the OPA used as it is the vital part of the scheme: operating angles, aperture and length, etc.
Conclusions/discussion - There should be mentions of drawbacks of using technique, namely scalability to ultra-high energies that ICF requires and the impact on the energy efficiency of the process once again limiting the final available energy.
The english quality is acceptable, although could be improved somewhat, I do not believe it to affect the understanding of the manuscript
Author Response
Dear Editors and Reviewers:
Thank you for giving us an opportunity to revise our manuscript, we appreciate editor and reviewers very much for your positive and constructive comments and suggestions on our manuscript entitled "Arbitrary time shaping of broadband low coherence light based on optical parametric amplification " (2308244). We have studied the comments carefully and have made revision in this paper. We have studied the comments carefully and have made revision in this paper. The responses to the comments from your reviewers are offered separately, and the main corrections in the paper and the responds to the reviewers' comments are as follows.
Author Response File: Author Response.docx
Reviewer 4 Report (New Reviewer)
The authors reported an arbitrary time-shaping technique scheme based on optical parametric amplification (OPA) ,that is an intersting arbitrary time shaping method ,and it is helpful to reduce the impact of LPIs.Experimental results including time-shaping contrast, rising edge, and spectral width are discussed in detail and seems good.I recommend this paper can be published in photonics.
The language can be improved, I just list some of them.
1.line 13, 'we propose an arbitrary time-shaping...'should be 'we proposed an arbitrary time-shaping...'.
2. line15, 'output characteristics are analyzed in detail' should be 'output characteristics were analyzed in detail''...............
3.line 59,'Insufficient research has been conducted ',‘researches on ...is not sufficient ’.
..........................
the manuscripts seems like an unedited one.Perhaps the athours has not uploaded the right file successfully. I suggest the editors help the authors replace this version.
Author Response
Dear reviewer, thank you for your professional review work on this article.
Author Response File: Author Response.docx
Reviewer 5 Report (New Reviewer)
This manuscript mainly discusses the potential of using low-coherence light to reduce the impact of laser-plasma interactions and proposes an arbitrary time-shaping technique scheme based on optical parametric amplification to improve the time-frequency characteristics of broadband low-coherence optical seeds. The paper analyzes the shaping process and output characteristics in detail and presents theoretical and experimental results that demonstrate the effectiveness of this technique in producing an arbitrary time-shaping pulse output with desirable properties.
Overall, the research topic of work about the arbitrary time shaping of broadband low-coherence light based on optical parametric amplification is interesting and has a wide range of applications for the research community of high energy density science. Therefore, I would like to recommend it to be accepted by Photonics if the authors can address my comments below:
1. The figures 4, 6, 8, and 8 are quite blurred. I cannot figure out what is exhibited these figures. I strongly suggest to replot these figures and utilize the vector graphic method when inserting them in the manuscript.
2. There are several previously published papers about laser-driven plasma. For example, [A. Arefiev et al., Phys. Rev. E 101, 043201 (2020)] and [A. Hussein et al., New Journal of Physics 23 (2), 023031 (2021)]. It would be better for the authors to cite them and add the pertinent discussion about what kind of studies have already been done in the previous work.
The English language of this manuscript must be improved before the acceptance.
Author Response
Dear Reviewer:
Thank you for giving us an opportunity to revise our manuscript, we appreciate editor and reviewers very much for your positive and constructive comments and suggestions on our manuscript entitled "Arbitrary time shaping of broadband low coherence light based on optical parametric amplification " (2308244). We have studied the comments carefully and have made revision in this paper. We have studied the comments carefully and have made revision in this paper. The responses to the comments from five reviewers are offered separately, and the main corrections in the paper and the responds to the reviewers' comments are as follows.
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report (Previous Reviewer 3)
No further suggestions for the authors
Author Response
Dear reviewer, thank you for your professional review work on this article.
Reviewer 5 Report (New Reviewer)
The authors have revised the manuscript following my previous comments. I don't have more concerns.
The quality of English language should be further improved.
Author Response
Dear reviewer, thank you for your professional review work on this article.
In response to your question, we have enlisted the help of a professional agency to improve the language level of the article.
Author Response File: Author Response.docx
This manuscript is a resubmission of an earlier submission. The following is a list of the peer review reports and author responses from that submission.
Round 1
Reviewer 1 Report
The authors report a new laser pulse shaping technique: it shapes the temporal profile of an OPA seed through shaping that of its pump, which has a low coherence. The seed pulse generated is reported to have a high contrast and a wide enough spectral width to support a fast rising edge. The reported results might be marginally OK to publish in a journal like Photonics. However its writing is not suitable for any scientific journal.
First, the authors should not invent/misuse technical terms, e.g., "...We demonstrate the shaped signal generated with a pump energy of 2.5GW/cm^2 and a signal power of 1W/cm^2..." Neither "energy" nor "power" is measured in unit of W/cm^2.
The manuscript is also full of grammatically wrong sentences, which occurs even in the abstract section, "... This scheme results the contrast ratios in excess of 300:1, the spectral width in excess of 40 nm, and the top modulation reduction of 4% are obtained. ..."
The first author is advised to make sure every sentence, and the coauthors are advised to read the manuscript at least once before it is sent out.
Reviewer 2 Report
Reviewer’s comments on ‘’Arbitrary time shaping of broadband low coherence light based on optical parametric amplification’’by Wang et al.
A simulation and experimental investigation of the effects of optical parametric amplification on seed laser pulses of 100 ps to nanosecond duration is presented. The peaks of pulses are amplified more than the leading edges and noise at the peak of e.g. a square pulse is reduced (in comparison to ‘’EOM shaping’’). Some useful work is presented. However, the implications for ICF are probably overstated as much higher contrast ratios than presented are needed in inertial fusion research.
The paper misses out important detail in the investigation. I suggest that the following issues need to be addressed and then better described:
1. 1. The ‘’contrast’ is defined (line 134) as ‘’ intensity ratio between the leading and trailing edges of the pulse’’ when in fact, the contrast here refers to the intensity ratio between the leading edge (at some undefined time) and the peak of the pulse. The authors need to define at what time before the pulse peak they determine the contrast and they need to better define the use of the ‘’contrast’’ term.
2. 2. Higher contrast results as shown in Figure 8 cannot be ascertained from the figure. In ICF, contrast ratios of 106 and higher are often required. The authors should show or quote separately, the improvement in contrast when dealing with seed contrast ratios of eg 100 -300. It would also be useful to cite in the introduction the contrast requirements for ICF.
3. 3. The authors need to define and briefly describe the term EOM shaping (lines 54 and 236).
4. 4. The authors have neglected to give any detail on the temporal measurements of pulse intensities (figures 8, 9 and 10) or the spectral measurement (figure 11). It is particularly difficult to understand how the sub-nanosecond temporal resolution shown in figure 9(c) was obtained. Without this detail it is not possible to assess the accuracy of the measurement results presented.
5. 5. Figure 3 and 4 are labelled to have the horizontal axis in nanosecond, but still have ‘’ X 10-9 ‘’ appended. The ‘’ X 10-9 ‘’ is not needed when time is measured in nanoseconds.
6. 6. Equations 1-3 need to be better described and some references/citations given as they are not immediately obvious.
Reviewer 3 Report
The work entitled “Arbitrary time shaping of broadband low coherence light based on optical parametric amplification” contains simulations and experiments.
The interest of the subject is clear, but the authors have not done a proper work both to explain their scientific contribution, nor in the presentation of results.
In section Principle and scheme, the authors give a set of coupled wave equations. They should cite were they have taken it form, since it seems to be incorrect: they use i and j for the imaginary number?
Besides that a major concern is that this set of equations are derived for coherent fields. How do the authors simulate the incoherent field? More details should be given.
In Figure 1 the output beams should be better aligned: residual pump aligned with pump and shaping signal with signal.
Figure 2. It is impossible to read anything. All figures along the text have very low quality and the authors have not done an effort to fulfil minimum requirements. All figures should be redone so that they are readable, have a proper size and fonts. In Fig. 7 the dichroic mirrors cannot be seen when printed in black and white. All letters are too small.
Insensity is in many figures. Should be Intensity.
If Pump starts with a capital, why not shaped?
In line 227 the authors claim that the contrast ratio exceeds 1:300. They should mention what is the contrast obtained by other authors.
Figure 10 b) and 11must be wrong. There are negative intensities!!!!!
Major English revision should be done. This includes, but it is not limited to, the following sentences:
Abstract:
This sentence has no meaning: To address the problem that high-frequency noise-like modulation is easily introduced in arbitrary time shaping of broadband low-coherence light, which threaten system safety and limit output capability.
Introduction:
Line 34 low time coherent has no sense. Do you mean low temporal coherence?.
Line 41 incoherent is written using a different font
Line 51 and 52 Proposes and demonstrates is the correct wording.
Lines 58 and 59 Similar is incorrectly employed here. Do you mean “approximately”?.
Principle and scheme:
Line 90 What does bit mean here?
Line 92 can be completely ignored is the correct expression
The variables in paragraph form lines 85 to 91 are not in place.
Simulations and experimental results:
Line 120 Presented above better than above.
Line 161 2.5 GW/cm^2 is a pump intensity, not a pump energy.
Line 162 What is increased in the pump? The energy, and therefore the intensity?
Line 216 arrangement better than structure
Line 221 I suppose you mean a solid state amplifier?
Figure 9 Where is c)?
Line 242 pump pulse, not pulse pump
Line 285 We analyze, not we analysis
References: Some times you use capitals. Other times you don’t. Please make it uniform.
