OpenLight (private) seems to get bigger and bigger every time I look at it.
If you’re curious about their public ecosystem outside of Advantest:
$JBL ( $SIVE partner ) for scaling PICs
$MRVL and $MXL for DSPs
$TSEM for the foundry.
$300394.SZ / TFC Optical (OSAT/subassembly)
Can often get exposure into private growth through public equities if you’re not an accredited investor.
Since optical players look very interconnected.