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Germanium Diodes Mean Progress Toward Silicon-Chip Lasers
David Orenstein writes "Teams at Stanford and MIT have each reported getting
strong light signals from germanium-based diodes on silicon at room temperature. Engineers have long sought to do this because, with further refinement into lasers, such diodes would allow for optical interconnects on chips. Optical interconnects could operate much faster and with less power than electrical (metal) ones that are becoming bottlenecks on current chips."
Now, lets have that lead to jobs for the west, rather than simply giving the tech to China. All fo this American paid for RD, should require that the work stay in the west.
Do you really want to deny the West the advances in manufacturing that the Chinese have contributed?
It's a global economy now. Get used to it.
John
The promise of making a laser from indirect bandgap semiconductors, then gathering investors, then losing the investors' money goes back to the Sixties at least.
Some scientists showed off SiC blue LEDs in the '60s that shown brilliantly like laser light, but were not the read deal. The real blue room-temperature laser had to wait for Nakamura and a direct bandgap material.
Doping, adding nitrogen, and adding defects to the lattice to produce more light is nothing new. Look at your stop lights. It's working there, but don't count on these indirect materials suddenly turning into lasers. No need to hold your breath.
A quick scientific note. Photons have a lot of energy, but not much momentum. You get hot on a sunny day, but not blown over by the sun. Electrons fall almost directly down in the bandgap diagram to produce light. This makes direct-gap semiconductors useful for lasers. The trick one can use is to provide momentum-shifting impurities to the lattice of an indirect bandgap crystal. The electron creates a photon by dropping directly down, but some other mechanism shifts the electron momentum to create an overall diagonal transition. It's not efficient, but it works.