Abstract

635nm wavelength laser diodes have been one of the most important components establishing the characteristics of DVD optical pickups. Especially, the spectral mode of laser diodes plays a great role in determining the signal-to-noise(S/N) performance of optical pickups, because the laser beam reflected from the disc is partly re-injected into the laser diode and interferes with the laser source[1]. In order to suppress this interference, the laser diodes need a self-pulsation property in inherent spectral characteristics, which is able to reduce the interference considerably. However, it is very difficult to obtain the stable self-pulsation modes in 635nm AlGaInP laser diodes. As a result, high frequency modulations of laser diodes were widely used to generate artificial pulsation modes in developing DVD optical pickups. Unfortunately, this approach causes parasitic effects and makes the DVD optical pickup complicated.

© 1996 Optical Society of America