I did some work recently making an octupled project. It is attached! You need to also use the supplied filterphase file for the filter in the design.
I used [1] as a beginning point.
[1] W. Li and J. Yao, “Microwave generation based on optical domain microwave frequency octupling,” IEEE Photonics Technol. Lett., vol. 22, no. 1, pp. 24–26, 2010.