Optical integration can be based off of Silicon substrates, however Silicon doesn't have the best optical properties. I believe that's the approach Intel is taking. Correct me if I am wrong.

Silicon is cheaper, more easily integrateable, and less toxic (however GaAs does exist in currently used components). Do we see these barriers being broken? Why did Intel not explore GaAs, as it makes a lot of sense from an optical properties perspective.

Thanks in advance for the feedback.