Beam Multiplication for Erasing Optical Phase-Change Recording
Original Publication Date: 1986-Jan-01
Included in the Prior Art Database: 2005-Mar-08
Phase-change media, such as media changing between an amorphous and a crystalline state, requires a slow heating and cooling process for erasing recorded data. An elliptical collimated beam passes through a sinusoidal grating and a focusing lens which divides the elliptical beam into a plurality of smaller elliptical beams along a given line. The effect of the beam division is to provide a low-intensity elongated series of small elliptical beams which enable erasing of any data recording in a phase-change record medium. The sinusoidal variations within the grating are disposed along the same line as the beam is elongated. A solid-state laser supplies an elliptical beam to a sinusoidal grating which is constructed using known techniques.