For those interested in gaining a bit of an understanding of PICs, a very good video from the Photonics Research Group - UGhent-imec
A nice intro to what a PIC is, waveguides, passive and active devices, how things fit together, strengths and weaknesses of different materials, why CMOS fabrication is important, product development stages, timelines, applications, etc.
Well worth the 54 minutes, IMO.
https://youtu.be/CBhdLTTbYoM