Caustics of Non-Paraxial Perfect Optical Vortices Generated by Toroidal Vortex Lenses

Round 1

Reviewer 1 Report

Please find detailed comments in the attached file

Comments for author File: Comments.pdf

Author Response

We are thankful to the Reviewer for the useful comments and suggestions, which allow us to improve the quality of the manuscript making it more clear for readers. We believe the corrections made address the Reviewer’s concerns making the manuscript suitable for publication in the journal.

All changes in the manuscript are highlighted by a color.

The file with detailed reply in the attachment.

 

Author Response File: Author Response.doc

Reviewer 2 Report

 

 

In the paper the formation of POV in non-paraxial regime with the toroidal lens and vortex axicon is studied. The stationary phase method is used and the results are compare with more precise numerical method based on expansion in conical waves.

The stationary phase methods allows reconstructing the caustic pattern of the generated images. Having it in hand the authors can draw interesting conclusions as for example that for large element (millimeters in diameter) the effect of vortex charge magnitude on the intensity distribution (bright ring) is negligible which explains the effect of perfect vortex beams.

The Figures presented in the paper illustrating the various case under study have a few parts. One of them is named “amplitude and topology”. Actually I am not used to the term “topology” in case of such a figures. Simply I do not know what it means. If the paper is to be readable for wider optical audience such points must be clarified at least by proper reference.

Generally, the paper is strongly mathematical and the final results obtained by stationary phase method are presented with no intermediate results. The paper is written in way that assumes that the readers have good background for this kind of presentation, which is not necessarily true. In other words the presentation is somewhat hermetic. Personally, I do not know how to change this situation. Most probably it must remain as it is. 

On the other hand the question of POV is important. So this kind of sophisticated mathematical presentation with some interesting results is a valuable contribution. That why I recommend the paper for publication

Author Response

We are thankful to the Reviewer for the useful comments and suggestions, which allow us to improve the quality of the manuscript making it more clear for readers. We believe the corrections made address the Reviewer’s concerns making the manuscript suitable for publication in the journal.

All changes in the manuscript are highlighted by a color.

The file with detailed reply in the attachment.

Author Response File: Author Response.doc

Reviewer 3 Report

The manuscript by Khonina et al. is an elegant study of caustics of perfect optical vortex beams. Perfect optical vortices have the specific advantage to be associated with ring diameters independent from orbital angular momentum, up to a critical value.
The manuscript is clear, results are conclusive and concepts are well illustrated with figures. 

I thus recommand publication. 

My single recommandation would be that the authors place their work in the more general context of optical vortices which would better stress upon the specific advantage perfect vortex beams. For instance, the caustics of Laguerre Gaussian beams and higher order Bessel bems and how their ring radius scales with azimuthal quantum number, have been extensively described in the literature. 

Author Response

We are thankful to the Reviewer for the useful comments and suggestions, which allow us to improve the quality of the manuscript making it more clear for readers. We believe the corrections made address the Reviewer’s concerns making the manuscript suitable for publication in the journal.

All changes in the manuscript are highlighted by a color.

The file with detailed reply in the attachment.

Author Response File: Author Response.doc