Baba, I think the final deliverable is associated with wafer-scale testing and is likely one of the guarded secrets in terms of knowhow. Automated testing requires probe points. Wafer-scale testing for electronic process has been established by industry with access points built into the design. For the optical side it is very different.

I am guessing that the optical access points require the creation of vertical mirrors. Which is likely part of the guarded secret to producing optical engines that can be tested while still in wafer form.

This is not based on any communications I have had with the company and I have not had time to research this but it makes sense at least to me. And again we are talking about the development of tools to do this. Additionally there is solder reflow requirements to fix the active die into the final position of the mating features. Again we are talking about automated processes to align the optical insertion points. So I think we are talking about refining the final steps for wafer scale production.

I think this is more about the order of doing things. You have to build all the components first then you have to put it all together. In other words the last step is not the hardest. The hardest has already been achieved which was the creation of the dielectric waveguides that meet DWDM standards.