We thank the referees for their positive reviews and excellent suggestions on improving the manuscript.
We have attempted to incorporate their suggestions with extensive new text providing additional details
on each of the two innovations reported. We have also added a new figure to further clarify the
technique exploiting the optical reversibility theorem.
We have modified the title of the manuscript and added language to the abstract to address the
concerns of the first referee about the reach of this article with its "polarimetry only" title.
We believe that we have addressed the referee's concerns and in doing so have significantly improved the
manuscript. 

Below is our detailed response to each of the first referee's comments.

Referee comment: - Either in Introduction or latest at the end of the section The Hall
C Compton Polarimeter:
- Introduce more properties of the electron beam (e.g. bunch charge,
bunch spacing - or is it a continuous beam?)

Response: A whole new paragraph had been added to page 2 ( right column, 2nd paragraph from top). This new paragraph provide details about the electron beam at JLab.


Referee comments: - Explain whether you're measuring in a single- or multi-electron
mode, i.e. do you have only one Compton interaction per bunch crossing
/ read-out window or do you record a whole spectrum of Compton
electrons at once? This is very important later to judge the challenge
the diamond detector and it's trigger and DAQ have to face!

- Page 3, left column: given that the use of diamond detectors as one
of the key points relevant (far) beyond Compton polarimetry, the
description of the detector, the trigger and DAQ lacks any emphasis on
what the challenges were and what really the key achievements were.

- Page 3, right column: what is the typical track rate and hit
occupancy per read-out frame? How large is the dead time? Although you
use several layers for triggering, in the end you apparently just
count the the hits in the the first layer? So how big a step would it
be to do real tracking and to determine the path of the electrons to
better the strip width?

Response: Significant new text had been added to address of all the above comments. For example, on page 3, left
column, lines 13 from the bottom on wards, text added to provide more details about the response of the
diamond detector and the performance of the readout electronics. Page 3, right column, 1st paragraph, details
about the track forming trigger, the trigger rates and the readout format is specified. Possible future
improvements are mentioned and necessary advances for other applications have been specified. Page 4, left column,
bottom of first paragraph, the key technological achievement is clarified.


Referee comment: - Page 4, right column: add some references / examples for the
statement that in previous polarimeters with Fabry-Perot cavity the
laser polarization was the dominant uncertainty.

- Just beneath: not being a laser physicist, I really have
difficulties to really understand the method you use to extract the
laser polarization. The given level of detail is probably perfect for
someone else who's working with laser cavities / laser polarization
measurement. But if you'd like to get the message across to a broader
audience, I'm afraid you need a bit more details, maybe even a sketch
of the setup.

- Top of page 5, left column: Is there any chance to improve the
bounds on the unknown impact of the reflections on the polarizations?
Or will ~0.2% be the ultimate limit on the laser polarization when
using a cavity?

- Page 6: in view of the relevance for future low energy electron beam
polarimetry and even a broader range of applications, it is not really
clear how the dominating systematic uncertainties (DAQ, beam position,
trigger) can be improved and what the potential of these improvements
could be.

Response: We have added a new figure and extensive new text providing details about the laser polarization
monitoring and measurement and also elaborated the key achievement with respect to previous polarimeters.
For example, page 5, midway through left column through top half of right column, new text and a new figure
added to describe the novel photon polarization measurement technique and how it compares to previous techniques.
The formalism of the optical reversibility theorem was also included. Page 6, left column, first 6 lines, text was
added to further clarify the uncertainty of the photon polarization measurement.

A complete list of all changes is attached with this response.

Thank you very much