Noise Considerations for Tomographic Reconstruction of Single-Projection Digital Holographic Interferometry-Based Radiation Dosimetry
Round 1
Reviewer 1 Report
Manuscript ID: photonics-2121398
Title: Noise Considerations for Tomographic Reconstruction of
Single-Projection Digital Holographic Interferometry-Based Radiation Dosimetry
Author(s): Tom Telford, Jackson Roberts, Alicia Moggré, Juergen Meyer, Steven Marsh
The main objective of this manuscript is to investigate the impact of noise from different known sources within the digital holographic interferometer to improve 3D DHI tomographic reconstruction. Then, the authors present their analysis in a single projection using the Invese Abel Transform. This approach is based on the FRED virtual model, which has been validated in previous work. The results are mainly shown on 2D images and profiles. But some details are not clearly established.
I would recommend making revisions to the manuscript and addressing the comments and some questions to be answered listed below:
Given the scope of Photonics Journal, this paper needs to properly define all acronyms and terms throughout the article, which are unfamiliar in optics and photonics.
The authors do not show images resulting from DHI in the base and modified states for the medium, nor the interferograms when the radiotherapy beam is applied, add some representative images.
Also include images with noise and indicate the type of noise.
Include the equations used to calculate the main metrics.
Since the work is based on the FRED model, describe this model for this specific application presented in this paper, including the main equations.
Indicate how the refractive index changes are found, as they modify the optical path and consequently the error measurements.
Further analysis should be added for Table 2.
The accuracy and error of the phase in a DHI setup needs to be included.
The results in Figure 7 show that the proposed method increases the noise compared to the original data, this would affect the objective of the work which is to use OC-2D DHI for applications in 3D dosimetry of FLASH radiation therapy beams even by averaging several images or reducing the amplitude of vibrations and atmospheric turbulence. What other factors are influencing these results?
Include how speckle scattered from object affects the ambiguity efficiency metric equations/measurements.
Author Response
Please see attachment
Author Response File: 
Author Response.docx
Reviewer 2 Report
In addition to the information presented by the manuscript I would like to know:
1. Are there additional sources of noise occurring in the system outside the interferometer (e.g., those, connected with laser beam power fluctuations, maybe others)? If so, how these noise types influence the radiation dose distribution reconstruction accuracy?
2. Figure 2. mentions the experimental measurements. However, further in the manuscript text there is no discussion of the experiments. So, it is not clear if any experimental measurements were implemented and how they correspond to the modelling results.
Author Response
Please see attachment
Author Response File: Author Response.docx
