Reference no: EM132190727

Question: Abstract: In this lab we calculated the track spacing on DVD's and CD's using a helium neon laser. For the DVD the calculated track spacing was 8.16E-7 m. For the CD the calculated track spacing was 8.30E-7 m.

I. Introduction

The purpose of this experiment was to calculate and compare the spacing between CD and DVD tracks by using media as diffraction gratings. Diffraction refers to various phenomena associated with wave propagation, such as the bending, scattering and interference of waves passing by an object or aperture that disrupts the wave. It occurs with any type of wave, including sound waves, water waves, electromagnetic waves such as visible light and radio waves. According to the principles of quantum mechanics, any physical object has wave properties. While diffraction always occurs, its effects are generally most noticeable for waves where the wavelength is on the order of the feature size of the diffracting objects or apertures. In our experiment we attempted to measure the distance between the tracks using media as a diffraction grating, a reflecting element whose optical properties are periodically modulated. Most commonly the diffraction gratings are realized as fine parallel and equally spaced grooves or rulings on material surface. When light is incident on a diffraction grating, diffractive and mutual interference effects occur, and light is reflected or transmitted in discrete directions, called diffraction orders.

II. Conclusion

The purpose of the particular lab is to calculate and compare spacing between the tracks on a CD and DVD by using the media as diffraction gratings. When laser light is shined onto a CD tiny grooves in the surface of the CD scatter the light in all directions. Some light waves create bright light while other waves eliminate each other to be clear. Specific names are associated with parts of pattern of light. The brightest spot of light is called Zero Order Maximum, the next part of bright spots is First Order Maximum, the next are second order maximum and so forth. After procedure is executed and all data is recorded, graphs and calculations are made.