Abstract: In order to provide a low noise laser beam, a noise reducing feedback network is provided which creates a noise reducing signal and provides that signal to the laser itself. In order to produce the noise reducing signal, the operation of the laser is monitored and the feedback signal is a direct result of this monitoring. Monitoring is accomplished by a fast-forward sense detector, which receives a portion of the laser beam from the operating laser. The output from this fast-forward sense detector is provided to an amplifier which inverts and amplifies the signal. A noise reduction feedback network then receives the amplified signal, appropriately filters this signal, and provides it to the laser itself so as to reduce noise in the laser-beam for the frequency band of importance for reading the recorded data from the optical medium.

Abstract: In order to minimize potential damage to a rewritable storage media, and to consequently extend the life of the media, the laser power is carefully controlled in order to avoide sharp power transitions. Rather than simply turning the laser power on to its full power level, the power utilized during writing dedicated sections of data sectors is transitioned from 0 to its full power level over a desired period of time. In this way, the thermal shock caused by repeated rewriting in these areas can be minimized, thus extending the life of the rewritable media.

Abstract: In order to provide a low noise laser beam, a noise reducing feedback network is provided which creates a noise reducing signal and provides that signal to the laser itself. In order to produce the noise reducing signal, the operation of the laser is monitored and the feedback signal is a direct result of this monitoring. Monitoring is accomplished by a fast-forward sense detector, which receives a portion of the laser beam from the operating laser. The output from this fast-forward sense detector is provided to an amplifier which inverts and amplifies the signal. A noise reduction feedback network then receives the amplified signal, appropriately filters this signal, and provides it to the laser itself so as to reduce noise in the laser-beam for the frequency band of importance for reading the recorded data from the optical medium.