High-density optical recording using a solid immersion lens

A solid immersion lens attached to a conventional objective increases the effective numerical aperture (NA(eff)) of an optical pickup and yields an areal recording density proportional to (NA(eff))(2). One version of this device, with an effective (NA(eff)) of 1.7, should be capable of very high density storage but would probably need a sealed system. Another simple configuration enables the use of this method for optical data storage in an unsealed environment and extends the spatial cutoff frequency 1.5 times. Experiments with these devices are compared with the full vector field theory of this type of imaging system.