What Is the Wavelength of a Laser Used in CD Data Retrieval?

[jsmith613]

Homework Statement

A CD stores data in digital form by encoding it into a grooves as a series of bumps of height 160 nm above the base of the groove. Explain how infromation is picked up from the CD using a laser and calculate its wavelength.

Can someone please explain how to do this question

Homework Equations

NONE

The Attempt at a Solution

I don't understand the question at all! Sorry!

 

[jsmith613]

If possible could someone also add a diagram to help me