Lab 3 Wave Optics

Allanah Rubi-Mooney

Physics 132 Section LZ

3/2/15

Experiment 3: Wave Optics

I. Abstract

This experiment explored the nature of light and the process of diffraction using a laser light and multiple different slits allowing the light to go through. The resulting light or shadow is displayed on a wall and calculations are made depending on the distance of the slit to the wall and the slit diameter. Due to the interference of the slit, some of the light waves are shown in phase or out of phase on the wall. We used this to determine wavelength.

II. Report Questions

1. Define wavelength and frequency in your own words and state the relation between them, (equation statement). (0.5 point)

The wavelength is the distance between one peak of a wave and the next peak of a wave. Wavelength = λ. The frequency is the speed of the waves and how many times they pass a certain point in the system. Frequency multiplied by wavelength λ equals the exact speed of the wave. C=λv where c is the speed of light in a vacuum 3.0E8.

2. Describe the pattern observed from diffraction around a straight edge, for the straight edge/opaque disks. Why do you think this pattern is diffraction and not interference? (1.0 point)

With the straight edge disc, there is a clear diffraction of light observed because of the flat line of light appearing on the wall outwards horizontally from the main dot of light. It is diffraction and not interference because of the light source only bumping into one medium whereas interference would be where two lights are interfering with each other.

3. When you illuminate the opaque holes in the straight edge/opaque disk using the laser through the lens, was there a light or dark spot at the center of the screen? (1.0 point)

There was a very bright spot and then other duller spots on either side of it.

4. Is there a specific reason for using lasers in this experiment, and not ordinary white light, if yes what is it? (there may be more than one...