Review Reports

Round 1

Reviewer 1 Report

The paper addresses a very interesting topic, like the acoustic detection based on optical technology. Please, find my suggestions:

- Please, introduce a brief description of the phase modulation spectroscopy principles in the Introduction 

- Please, clarify the acronym when they are firstly used: CMOS (at row 57), RI (at row 57), SNR (at row 59), ICP, PECVD (at row 88)

- Please, clarify the expression "attaching to the atmosphere" at row 68

- I suggest to add the description of each layer in Figure 1(a) and to provide a picture of region with groove and a region without groove

- Please, provide the overlapping factors at different groove between light and the surrounding medium at row 107 

- Please, provide a picture of the different etched regions in the two extreme limits at row 114

- Please, provide formulas describing how FWHM and ER were calculated.

- Please, replace "106" with "10⁶" at row 131

- Please, specify in the caption which sensor was tested in Figure 3 (b) and (c)

- Please, explain why the offset signals of the resonance curves in Figure 3 (b) after 0.02 s and (c) are different. 

- Please, use as a lower limit of -4dB on the y axis of Figure 4 to better distinguish curves

- Please, check the caption of Figure 4: 4 curves ar shown in the picture but only 2 were described

- Please, provide and comment the different offsets of the sensitivity curves in Figure 5

- Please, replace "Pin" with "P_in" at row 202

- Please, specify how you define the baseline to calculate the SNR in Figure 6

- Please, provide the position of the measured peak in Figure 7

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Reviewer 2 Report

In this manuscript, the authors anayzed a ring-shape device for aoucsitc sensing. Conceptual illustration, experimental results were presented. It was claimed that the device has promising acoustic detection capability. This is a well written manuscript, it should be interesting to the readers in this field. 

Comments:

1. Performance comparision should be carried out with the results in previous ring-shape sensors. What is the advantage/difference of the proposed devices?

2. What is the size of the device? marker is suggested to be added in Fig. 1

3. From the abstract, it seems that high Q is recommended. However, a high Q device yields smaller deltaV as suggested in Fig. 2.

4.Where is the source of the acoustic in Fig. 3?

Author Response

Please see the attachment.

Author Response File: Author Response.docx

Round 2

Reviewer 1 Report

I thank the authors for the careful corrections and I only suggest to replace "Figure 4" at row 278 with "Figure 5".

Reviewer 2 Report

The authors have addressed all the issues