Lab 11. CD Diffraction

Introduction
         
     Using the procedure that Sameer has developed to test the CDs' grooves distances and compared it to the manufacturer's standard value, 1600 nm. 

Procedure

     PART 1. Find the wavelength of laser.

Arrange the laser, screen and diffraction grating.

     PART 2. Find the distance between CD groove.

Data/Discussion

  Calculation without uncertainty.

Calculation with uncertainty. 

PART 1. Wavelength of Laser

PART 2. Distance of CD groove

     By comparing the manufacturer's standard value, 1600 nm, the results gave  error range of 6.63%. This percentage error calculation is based on the uncertainty while the direct measurement gave 8.31% error. The uncertainty of measurement gave more accurate result that closer to the standard value of 1600 nm.

Summary

     The procedure that developed by Sameer for testing the quality for CD is a great tool to test the distance between the grooves on CDs and the consistency of groove as well. Comparing the values of manufacturer's standard value of 1600 nm, the CD that we tested has closer quality to the standard CD (1494 +/- 148 nm).