Flexible Modulation of Perfect Vortex Beams by Combining Coherent Beams
Round 1
Reviewer 1 Report
Comments and Suggestions for Authors
The paper presents yet another method for generating PVB. It is realized by combining 24 beams with proper phase and/or tilt. The suggested experimental method is sketch in Fig.1. The experimental system is rather complicated which is a disadvantage of the proposed method. Author do not used this experimental system. They preform numerical calculations based on the theoretical formulas derived in section 2. The obtained numerical results are highly simplified comparing to what could be get in real experimental system. As author claim the obtained PVBs have high modal purity. However, the question of modal purity is strongly related to the imperfections in experimental system. This imperfections are evaluated in this theoretical work. So, we do not know what real quality of the generated beam could be. The PVB shown in Figure 2c has large radius (about 0.1 mm). PVBs having smaller radius are more useful for practical applications (like optical trapping). The question is if we can make it smaller could be addressed by the authors. In line 83 we have: “orthogonal coordinates (x0y) is transferred to be Cartesian coordinate system (r ,fi ) , and the formula (1) can be expressed to be….” I think that it should be “… Cartesian coordinate system is transferred to polar one (r,fi)…”.
The work is not of high quality but the proposed method and examples presented by the author (theoretically) can be interesting for some group of readers. So I recommend the paper for publication after addressing my minor remarks.
Author Response
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Reviewer 2 Report
Comments and Suggestions for Authors
Comments for author File: 
Comments.pdf
Comments on the Quality of English Language
Author Response
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Reviewer 3 Report
Comments and Suggestions for Authors
In this paper, the authors introduced a new method to produce Perfect vortex beams (PVBs) using the coherent beam combining (CBC) technique. The Perfect vortex beams (PVBs) and fractional perfect vortex beams are known to have the advantage, over the standard vortex beams, of stable light field distribution regardless of the topological charges. That’s why they are desirable in various applications, such as optical communications, micromanipulation of particles, optical tweezers, and so on. Besides, CBS has proven to be an efficient concept for generating structured light beams with flexible modulation. In this work, the authors demonstrated that within the CBC technique and using piston phase and tilting phase controlling parameters, many PVBs as well as fractional PVBs can be generated with a flexible modulation of their field distributions. The authors analyzed numerically the propagation dynamics of the generated beams, under different beam parameter conditions. The relationships between the modulation parameters and the properties of the generated PVBs are established. The research topic is interesting and the adopted technique, i.e., modulation by piston phase and tilting phase in the CBC system, offers an effective tool to generate PVBs with flexible intensity profiles. The manuscript is well written, and the theory model seems correct, and the simulation analysis outcomes are consistent. The research may be beneficial to many advanced laser applications. In conclusion, I think, this paper deserves publication in "Photonics" in its present form.
Author Response
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Reviewer 4 Report
Comments and Suggestions for Authors
The manuscript titled “Flexible Modulation of Perfect Vortex Beams by Coherent 2 Beam Combining” reports the simulation of the generation of perfect vortex beams by coherent beam combining. In this view, the proposed work is timely, and the results are promising. The manuscript is technically sound, well-structured and allows fluent reading.
1. Introduction: the authors give an overview of studies of structured beams. To give the readers a comprehensive overview of this promising field I suggest including the following reference in the manuscript: "Space-time vector light sheets," Opt. Express 29, 37225-37233 (2021) and Demonstration of speckle resistance using space–time light sheets. Sci Rep 12, 14064 (2022)”. The authors report a new structure beam which is a nondiffracting beam called “space–time light sheet” in this study authors compared several types of beams including Gaussian beam, Airy beam, and Bessel Gauss beam, and they show that the ST light sheet exhibits strong speckle resistance.
2. In the introduction line 33, authors say “There are several efficient methods to generate PVBs…” I suggest authors give some practical examples. I suggest also checking this paper Opt. Express 29, 37225-37233 (2021).
3. What limit the perfect vortex beams compare to the other vortex beams in this study?
To my opinion, this manuscript can be recommended for publication before the authors give the improvement.
Author Response
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Round 2
Reviewer 2 Report
Comments and Suggestions for Authors The revised version of the article looks much better with the
suggested changes, size of the bars, etc. There are some small details that still need to be changed, such
as the word "penitential" on line 311, where we think "potential"
should appear, and some more that can be corrected in the editing
phase. Without further ado, we recommend publishing the job. Comments on the Quality of English Language Some small details should be changed as shown in the general review report.
Reviewer 4 Report
Comments and Suggestions for Authors
Authors addressed all the comments, the paper can be accepted in the journal.
