I was looking into the highest bandwidth optical transceivers. 400Gbps were easy enough to find so thanks for posting this. I honestly didn't know there were 1.6Tbps transceivers like this.
One note: I believe the SMF max fiber length is 2km not 1m [1]. The data sheet [2] also says:
Bidirectional is a lot like biweekly. Biweekly depending on context means twice a week or once every two weeks and bidirectional can both mean per direction and total of both directions.
I'm only a single datapoint but I've never encountered that usage. My understanding of a bidirectional link is that it meets the same spec in both directions simultaneously. It's important precisely because many links aren't bidirectional, sharing a single physical link between two logical links.
The video is about a 2x1 link, which the author hopes to eventually scale up to 3x4 using 40 gig transceivers. I'd say thunderbolt is probably safe in the near future.