1. Two-Wavelength Laser Diodes for DVD Playback

Low Noise Regulated Technology
In optical disc systems, light reflected from the disc with irregular amplitude, the so-called "returning light", can disrupt laser operation and generate noise. While this noise is usually excluded using a high-frequency superposed circuit, these high-frequency modules have a high current consumption and undesired radiation countermeasures are required.
Sony achieve a low-noise laser that does not require a high-frequency superposed circuit by using a self-pulsation type device on the DVD side and a gain guide type multimode laser on the CD side. This allows both costs and power consumption to be reduced, and also obviates the need for undesired radiation countermeasures.

Facet Strengthening Technologies which Achieve a High Resistance to ESD Damage
Catastrophic optical damage (COD) is a problem that prevents achieving higher output in laser diodes. If the laser is driven at a level above the output limit (COD output), the optical emission surface (facet) of the laser chip melts because of heat generation, leading to a cessation of light generation. Sony has applied their unique laser chip facet strengthening technologies resulting in an increase in the output limit to twice that of previous Sony products.
The rated output have been increased by 25% over earlier products and this allows to provide greater flexibility in optical system design and to handle limited optical systems. Laser diodes are easily damaged by ESD and other instantaneous high currents, and thus antistatic and anti-surge measures are absolutely required in manufacturing lines that handle laser devices. Conventional self-pulsation type lasers usually have a low resistance to ESD as compared to the lasers used for recording. The laser diode, however, achieves a level of 80 V or higher for the DVD side forward direction ESD resistance (machine model test). Thus it has a resistance to ESD damage twice that of conventional products and can enable reduced costs in antistatic measures.