Using Laser Pointer to Measure the Data Track Spacing on CD´s and DVD´s

Document Type : Original Article

Authors

1 University of Technology- Department of Applied Science ,Iraq.

2 Prof. Dr., Al-Mustansiryah University, College of Education, Iraq.

10.21608/iugrc.2016.91150

Abstract

We have probably noticed the colourful patterns "reflecting" from the shiny surface of a CD and DVD disk. What we are seeing is actually diffraction of white light, and the rainbows of colour are diffraction patterns. In this project, we will learn about how diffraction patterns are generated when CD and DVD disk are used as reflecting and transmitting diffraction grating . Further, the microscopic spacing of data tracks on a CD and DVD disk can be measured using a red laser pointer. AFM (Atomic Force Microscope) images indicates how close the track spacing to that macro-scale data that (optically measured).