Self-coupled optical pickup

Abstract When a double- or multi-heterostructure GaAlAs laser is irradiated by its own output laser beam, an oscillatory shift of about 25 MHz is observed in the electric conductivity of the laser. When the pumping current is clamped, the shift in the voltage across the laser electrodes amounts to the order of a millivolt at a return ratio of about 10%. This suggests an availability of the laser as an optical pickup in some types of optical memory playback systems.