Archiving Media -Optical Laser Type & Archive Media Capacity

Another important factor is the type of laser being utilized by the media’s optical drives to write and read data. The following illustration provides greatly enlarged examples of the comparative size of the laser when focusing on the media’s surface. Accordingly, the smaller the focal point of the laser, the higher the data density.

As exemplified below in the comparison of CD, DVD and UDO/Blu-ray, the magnified density of the recording surface clearly shows significant improvements based on the focal diameter of the laser.

Mark size of the laser on the media is determined by

• Wavelength of the laser (spot size)
• Power of the objective lens (spot size)
• Pulse power and duration (pulse width)

Laser Size and Shape Comparison:

Optical Laser Comparison - Recording Density: