From the "Abstract", it looks like an important patent regarding the reduced optical losses with Poet's optical interposer.
Date of patent : June 27th, 2023
Patent number : 11686906
Inventor : Suresh Venkatesan, Los Gatos CA (USA)
Self-aligned structure and method on interposer-based PIC
https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/11686906