Self-Excited Oscillation Laser Diode
The noise characteristics rating is one of the most important performance parameters in laser diodes. In particular,
even lower noise levels than those in the 780-nm band CD lasers are required in the 650-nm band lasers used
in DVD pickups. In optical disc systems, the light reflected from the disc surface returns to the pickup with
irregular intensity. This is referred to as return light,and the influence of this return light disrupts the laser operation, causing noise. In earlier systems, the super imposition of a high frequency signal in the 300 MHz to 1 GHz range was used to reduce noise,but this technique has the following