Light delivery for heat assisted magnetic recording

The storage density of commercial hard disc drives has historically increased at an annual rate ≥60%. Densities exceeding 100 Gb/in² have been demonstrated in the laboratory. Heat-assisted magnetic recording, to assure thermal stability of the data, holds the promise of enabling magnetic storage densities greater than 1 Tb/in². There are many technological hurdles to overcome before this can be realized. Perhaps one of the most challenging will be to develop a technique for concentrating optical power in a spot less than 50 nm in diameter which is coincident with the recording field. Various techniques have been proposed for doing this, but we must now improve the initial simulations to more realistic models which include the entire system and we must reduce these ideas to practice. It is likely that any successful technique will make use of short wavelengths and the surface plasmon resonance effect.