Enhancement of positive contrast in optical recording

摘要

This invention provides a superior process for optical information storage by providing a mixture of azaannulene compounds in the recording layer. The recording layer exhibits large positive contrast in the recorded areas upon recording with laser radiation. The positive contrast is surprisingly larger than the positive contrasts exhibited by recording layers made from the individual azaannulenes included in the mixture, and because of this large positive contrast the sensitivity of the medium is high and consequently low laser powers are sufficient to effect the recording.