PASCO OS-8170A Brewster’s Angle Accessory - Manual (Page 14)

Brewster’s Angle Accessory Model No. OS-8170A
14
®®
1. To determine Brewster’s Angle, use the Graph display (“Norm +” versus “Angle”). In the
Graph, select a group of data points on both sides of the apparent minimum.
2. Click the “Fit” menu in the toolbar of the Graph
and select “Quadratic Fit”. (Note: Double click the
Quadratic Fit legend box to open the Curve Fit
dialog box. Make sure that “Fit with first selected
data point at X = 0” is NOT selected.)
Questions
1. From the curve fit, how do you determine the minimum of the function?
2. Use Brewster’s Angle to calculate the index of refraction of the acrylic “D” Lens using
Equation (3) tan
p
= . What value should you use for n
1
?
3. Would Brewster’s Angle be larger or smaller for light in air reflecting off water?
4. Would Brewster’s Angle be larger or smaller for light in water reflecting from the “D” Lens
(that is, if the “D” Lens were submerged in water)?
5. How do polarized sunglasses reduce glare? Which direction is the axis of polarization in a pair
of polarized glasses? How would you check this?
6. Which direction is the axis of polarization of the light reflected from the “D” Lens?
7. How is the index of refraction affected by a change in the wavelength of the laser?
Quadratic Fit
legend box

n
2
n
1
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