Semiconductorization of Photonics

I googled the term to check my spelling and the following was the first result:

POET Tech Term of the Week: Semiconductorization of #Photonics What Is It: The term refers to the use of traditional semiconductor manufacturing methods in the world of photonics.Aug 7, 2023

The patent that Mironclaw posted was Published on Nov30. It is a continuation of the Loopback patent filed in 2021 and shows considerable detail with numerous configurations. https://image-ppubs.uspto.gov/dirsearch-public/print/downloadPdf/20230384516 

Why this patent is important:

It provides a mechanism to allow end to end testing and burnin using only electrical probes instead of the time consuming approaches typically used to test photonic circuits. The following video provides an example of how photonic circuits are tested today. This approach uses gratings at the surface of the wafer which are entry points for light to connect into the PIC. The light source requires time consuming alignments which can be observed in this video. 

https://www.youtube.com/watch?v=izM33rfVVc4

For light to connect at the edge of planar circuits (light emitting waveguides) for testing it becomes much more complicated. R&D to find an adequate solution is still ongoing.

What POET has achieved is a much simpler and effective process that allows testing via electrical probes (standard practice for semiconductor testing). So instead of using external light sources for testing POET uses a very efficient approach. The lasers are energized through electrical test points on the wafer and a loopback waveguide connects the transmit circuit to the receive circuit to provide end to end testing and burnin. The loopback is removed during dicing and replaced with fiber coupling points.

Numerous configurations are provided in this patent for various design layouts depending on the application functionality  required.

Figure 14 is interesting. 2 quad laser arrays (8 lasers) connected to 8 modulators. Those 8 channels are then combined in an 8 channel mux which connect to the single loopback waveguide. Those 8 channels are looped back into the 8 channel de-mux then to the receiving devices. Very compact engine with both fully integrated transmit and receive in a single engine…800G  or 1.6T.