Hector Martin

That requires the next phase I'm waiting on: nm-scale lithographic printing on silicon.

that's what electron guns are for, right

I've thought about whether you could do it radially with a modified bluray drive...

A friend did something similar, but not nm-scale (just for decorative purposes). You kind of need a patterned surface for tracking though.

I'm not sure you could sensibly modify a typical pickup to track without a pre-groove to lock on to (i.e. blank disc).

There might be some other side channel you could track by...?

As far as I know, without the optical feedback from the pickup itself onto the pre-groove, focus are tracking effectively become open-loop.

Angular tracking is a problem too (normal burners just don't care except roughly on average). Friend built some FPGA-based PLL thing.