How do lasers read CD’s?

Question

How do lasers read CD’s

Answer 1

When a CD is made, it is digital information (ones and zeros) that is encoded into the plastic disk. For example a 'zero' means that a microscopic pit is formed in the plastic, while a 'one' means that no hole exists (the original plastic is left alone).

When the laser beam scans these pits it will pick up a series of pits or no pits depending on the ones and zeros pattern. When the infared laser encounters no pit, the beam is reflected back to an infared light sensor. When the beam hits a pit, the beam is absorbed so no light gets reflected back to the detector.

So, the detector sees a pattern of light, no light, etc. as the disk spins and recreates the pattern of ones and zeros, which contain the music or data.

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Answer 2

time of flight. the laser bounces off the surface or off holes. it takes longer for the laser to bounce out of the holes and the controller tracks them as ones or zeros.

Answer 3

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