Interlaced Laser Beam Scanning: A Method Enabling an Increase in the Throughput of Ultrafast Laser Machining of Borosilicate Glass

Round  1

Reviewer 1 Report

This manuscript discuss the two laser beam scanning methods, (i) bidirectional sequential scanning method (SM) and (ii) bidirectional interlaced scanning method (IM) for micromachining borosilicate glass plates. The new experimental result for the enhancement of ablation depth by interlaced scanning is interesting. The results provide some useful information for glass machining; but there are several minor issues which must be addressed before this article meets the criteria of publication:   

1.     Please cite the below papers and discuss the effect of the beam reflection effect for different scanning strategies.

L. M. Machado, R. E. Samad, A. Z. Freitas, N. D. Vieira, and W. de Rossi, "Microchannels Direct Machining using the Femtosecond Smooth Ablation Method," Physics Procedia, vol. 12, Part B, pp. 67-75, // 2011 

2.     In the Introduction section, please add the discussion on 3D surface structuring by fs laser and citing the below references.

M. Pfeiffer, A. Engel, S. Weißmantel, S. Scholze, and G. Reisse, "Microstructuring of Steel and Hard Metal using Femtosecond Laser Pulses," Physics Procedia, vol. 12, Part B, pp. 60-66, // 2011.

Rodríguez, A. Arriola, T. Tavera, N. Pérez, and S. M. Olaizola, "Enhanced depth control of ultrafast laser micromachining of microchannels in soda-lime glass," Microelectronic Engineering, vol. 98, pp. 672-675, 10// 2012.

C.-W. Cheng, X.-Z. Tsai, and J.-S. Chen, "Micromachining of stainless steel with controllable ablation depth using femtosecond laser pulses," The International Journal of Advanced Manufacturing Technology, vol. 85, pp. 1947-1954, 2016// 2016.

Author Response

Response to comment #1:

We have cited this paper in Section 4.4 (see Lines 347-348).

Response to comment #2: 

We have cited the articles of Pfeiffer [6] and Cheng [7] in Line 48. This sentence covers both picosecond and femtosecond lasers, highlighting their ability to machine different materials. The article of Rodriguez discusses the influence of laser machining parameters on the ablation rate of soda-lime glass, and focuses mainly on the generation of small channels.  Similar work has already been presented in other publications cited in this manuscript, therefore we did not include this reference.

Author Response File: Author Response.pdf

Reviewer 2 Report

In this work, the authors compared the laser beam ablation scanning methods. One is a  bidirectional sequential scanning method (SM) and the other is a  bidirectional interlaced scanning method (IM), The following questions should be answered before the further procedure.

In the title, the authors used the word of "efficiency". However, I did not find the definition and the use of the efficiency in the article.

The reason why the interlace distance is three times of offset? Is the offset is related with the ablation diameter of a crater?

In the abstract line 28, the authors mentioned about the therma effect. However the authors did not mention about the thermal effect in the article.

In Fig. 4, the ablation depth by SM is shallower than that of IM. The authors need to explain about it.

In Fig. 10, the authors need to explain why the results are obtained at the laser energy of 46.5 μJ.

Author Response

Response to Question 1:

To avoid this confusion, we modified the title by deleting the word “efficiency” and adding the phrase “throughput of” (see Line 3). Now the title is “Interlaced laser beam scanning: a method enabling to increase the throughput of ultrafast laser machining of borosilicate glass”.

Response to Question 2:

We assume that the reviewer refers this comment to Figure 1 in Section 2. This figure illustrates a particular case of interlacing where the interlace distance is equal to 3*ΔH.  In reality, the interlace distance can be any value that is a multiple of ΔH, where ΔH is the hatch distance selected for machining.  The offset is not related to the diameter of an ablated crater. 

Response to Question 3:

Thanks for spotting this. We deleted this part of the sentence from the abstract and added “and hence reduced shielding of the machined area” (see Line 28). 

Response to Question 4:

Good point. We have to agree that from Section 4 is not clear why the ablation depth is higher in IM, therefore we provided a short summary in Conclusions – see Lines 353-357.

Response to Question 5:

This pulse energy as well as other laser parameters were chosen because they correspond roughly to the midpoint on the graphs of Figure 7. We added this info in Line 318.

Author Response File: Author Response.pdf