GOALS

Physics

• Study diffraction and interference effects with a He-Ne laser.
• Learn how to measure dimensions of very small objects.
• Measure the wavelength of He-Ne laser light.

• Shine the laser through prepared slides or objects such as hair and measure light pattern dimensions.

Errors

• Find wavelength of the laser from several of your measurements and see if it agrees with known value.

Question (work out in lab book before lab)

1. Suppose that the viewing screen (Fig. 2) is not quite perpendicular to the laser beam, does this cause any trouble in determining angles associataed with the intensity pattern? What are the consequences of measuring distances on both sides of center on the screen (symmetric patterns) and using the average value to compute angles?

References

• Halliday and Resnick, 3rd Edition, Ch. 40, 41
• Much of Exp. 5 also applies
• Young, University Physics, 8th Edition, Ch. 37, 38, 40-6