The electret recording system
K. Amanullah · IEEE Transactions on Consumer Electronics · 1994
Describes a new system for recording and reproducing information on a dielectric material by selectively forming electret sites using the energy from modulated laser beams. The recorded information is read back by a specially constructed MOS FET playback head which detects the presence or absence of electric fields produced by stored charges in the electret sites on the tape. The dielectric materials must have properties which are constant and stable over a wide rage of temperatures and frequencies and must be able to retain the electric charges for long time.>