High-density optical recording with (Ga,Al)As DH lasers

Abstract

(Ga,Al)As lasers were employed to optically machine a series of 1‐μm‐diam holes in 200–300‐Å‐thick films of tellurium on polymethylmethacrylate substrates at repetition rates as high as 10 MHz. By modulating the hole repetition frequency, limited bandwidth video signals were successfully recorded. The hole machining was accomplished with lasers which operated in fundamental transverse and lateral mode at high pulsed power (typically greater than 150 mW), in conjunction with a high‐collection‐efficiency focusing system. The lasers were operated at low (⩽20%) duty cycle in order to minimize internal heating. The hole sizes obtained and the repetition rates achieved are appropriate for a high‐density optical recording system.