Optical Trapping of Chiral Particles by Dual Laser Beams
Round 1
Reviewer 1 Report
This work shows numerical study of chiral particle trapping by dual laser beams. The authors show many numerical results to demonstrate the trapping capability of dual laser beams. This is a solid study. I have a few suggestions for the authors to improve the manuscript.
1. In the introduction section, the authors begin with the origin and development of optical tweezers. This is a good beginning for readers to get a better understanding of this research field. However, the given references are too old. I suggest the authors to add more recent publications, so that readers can know what’s the direction of this field, for example, Adv. Mater. 32, 2001994 (2020), J. Biomed. Opt. 26, 070602 (2021), Nanophotonics 8, 1023 (2019), etc.
2. In Figure 1, the authors give a schematic diagram, I suggest the authors present a better particle image that can show the property of chiral.
3. In figure 10, the authors show the different trapping performance for particles with different parameters. However, it is difficult to get compare this trapping performance due to the crowded data. A simplified and conclusive curve can be better.
Author Response
Dear editor,
Thank you for your kind attention and the reviewers’ helpful comments on our manuscript titled “Optical trapping of chiral particles by dual laser beams” (ID photonics-2515030).
According to the reviewers’ comments, we have revised majority of our paper to make it more concise and clearer. For detailed responses, please see the appendix. We hope the paper has been improved greatly and will meet the requirement of your journal after revising. We will be very glad to hear more comments on it.
Thank you again!
Best regards,
Jing Bai, Zhen-sen Wu
Author Response File: 
Author Response.docx
Reviewer 2 Report
The authors discuss trapping of chiral particles by dual laser beams. Due to the nature of the chiral medium, some interesting features appear that distinguish the results in the paper and justifies the research.
Specifically, the detailed analysis of the influence of the beam parameters and particle properties on trapping force may be of interest to some experimentalists.
While there is an extensive theoretical introduction, some inconsistencies hinder the understating of the equations. There are several problems that I think should be addressed in this regard:
1) After Eq (1) beam parameters are introduced, including different frequencies and wave numbers of the beams. Later, in all calculations only a single frequency with zero phase difference is used. This might unnecessary complicate some equations, and should be at least discussed before Eq (13), where the sum of the fields is presented without the temporal part.
2) Eqs (20-23) use parameters x_0, x_1, x_2 that are different from those used before, which also hinders the understating.
There are also some problems with the figures:
3) Fig. 4 is of poor quality. It is particularity noticeable if one tries to read the numbers. Also, the field amplitude units should be included.
4) Fig. 6-13 include calculation results, but also include some solid lines that I assume are some kind of approximation/interpolation/fit. It should be clearly stated what they are.
Generally, I am satisfied with the extensive analysis of the parameters in the paper. However, certain aspects that are important for the experiment are not discussed.
5) What happens if the phase discrepancy changes from 0? What happens if the laser beams angle changes slightly due to some misalignment? What happens if the polarisation is not exactly as presented?
At least some discussion of the requirements should be made. If it is not that important, it should be said so.
6) There is inconsistency in the use of "waist radius" and "waist width". I feel like only one should be used.
On the whole, I find the paper will written and may be accepted after minor revisions.
As a final comment, I recommend publishing the code in an open source repository to make the results and the paper itself more useful to the community.
Author Response
Dear editor,
Thank you for your kind attention and the reviewers’ helpful comments on our manuscript titled “Optical trapping of chiral particles by dual laser beams” (ID photonics-2515030).
According to the reviewers’ comments, we have revised majority of our paper to make it more concise and clearer. For detailed responses, please see the appendix. We hope the paper has been improved greatly and will meet the requirement of your journal after revising. We will be very glad to hear more comments on it.
Thank you again!
Best regards,
Jing Bai, Zhen-sen Wu
Author Response File: Author Response.docx
Reviewer 3 Report
The Authors propose an analytical method for studying the radiation force acting on chiral spheres generated by dual laser beams. The manuscript is well written and an interesting approach for trapping is reported. Here, my comments:
- As properly reported by the Authors in the Introduction, common trapping setups use single laser beam. Trapping of proteins (see, i.e, Ultrasensitive detection of a protein by optical trapping in a photonic‐plasmonic microcavity. Journal of Biophotonics, 5(8‐9), 629-638, 2012 ) and virus (see, Nanoscale optical trapping by means of dielectric bowtie. In Photonics (Vol. 9, No. 6, p. 425). MDPI, 2022.) have been demonstrated in literature. However, during the last decades, in order to ensure statistical study, the multiple optical trapping have been explored, by using single laser sources (see, i.e, Exploring the limit of multiplexed near-field optical trapping. Acs Photonics, 8(7), 2060-2066, 2021.) or multiple laser beams (see, i.e., Construction of multiple-beam optical traps with nanometer-resolution position sensing. IEEE journal of selected topics in quantum electronics, 2(4), 1066-1076, 1996). Therefore, besides an enlargement of the literature, as reported above, the Authors should report the main limitations of single laser beam – based setup, to help the reader in rating the benefits of dual laser beam.
- The novelty of the proposed analytical model should be more stressed.
- An efficient trap should provide a stability larger than 1. The stability is expressed as the ratio between the potential work and the product kb T, where T is the temperature within the trapping site (see, i.e. Comparison of silicon photonic crystal resonator designs for optical trapping of nanomaterials. Nanotechnology, 21(30), 305202, 2010). Please evaluate it.
Author Response
Dear editor,
Thank you for your kind attention and the reviewers’ helpful comments on our manuscript titled “Optical trapping of chiral particles by dual laser beams” (ID photonics-2515030).
According to the reviewers’ comments, we have revised majority of our paper to make it more concise and clearer. For detailed responses, please see the appendix. We hope the paper has been improved greatly and will meet the requirement of your journal after revising. We will be very glad to hear more comments on it.
Thank you again!
Best regards,
Jing Bai, Zhen-sen Wu
Author Response File: Author Response.docx
Round 2
Reviewer 1 Report
The manuscript has been improved a lot, and can be published now.
Author Response
Dear editor,
Thank you for your kind attention and the reviewers’ helpful comments on our manuscript titled “Optical trapping of chiral particles by dual laser beams” (ID photonics-2515030).
Thanks so much for the reviewers’ constructive comments and suggestions on our manuscript.
Thank you again!
Best regards,
Jing Bai, Zhen-sen Wu
Reviewer 3 Report
The Authors have modified the manuscript according to the Reviewer suggestions. Please improve the quality of Fig. 6-13.
Author Response
Dear editor,
Thank you for your kind attention and the reviewers’ helpful comments on our manuscript titled “Optical trapping of chiral particles by dual laser beams” (ID photonics-2515030).
According to the reviewers’ comments, we have revised our paper to make it more concise and clearer. For detailed responses, please see the appendix. We hope the paper has been improved greatly and will meet the requirement of your journal after revising. We will be very glad to hear more comments on it.
Thank you again!
Best regards,
Jing Bai, Zhen-sen Wu
Author Response File: Author Response.docx
