Phys 152 - BlackBoard Notes: Diffraction and Interference

Diffraction & Interference - 152
BlackBoard Notes

======================= Photo - Click for a Larger Version =============================

Note that the 152 lab is set up in the 104 lab, hopefully in succesive weeks. In that case, the blackboard notes will only need slight modification

======================= Photo - Click for a Larger Version =============================

AARRGGHH! I switched from mλ… to nλ… in Experiment 2. Need new photo in 2026!

======================= First Board Section =============================

Three experiments (in any order !):

1.   Observe diffraction, interference patterns (single- and double-slit)
2.   Measure λ of a red laser **A Lab Practical Skill**
3.   Measure extreme violet and red λ's of visible light

Room Setup Map:

Note: the three optical benches from Experiment 2 have been removed. It doesn't really matter if this image is changed, since nobody looks at it.
$Diffraction room map$

======================= Second Board Section =============================

(1) Diffraction, interference – a qualitative analysis:

.

Single Slit Single Slit:
How does a wider slit width
affect the diffraction pattern?

Double Slit Double Slit:
How does a greater separation between slits
affect the interferece pattern?

======================= Third Board Section =============================

(2) Wavelength of a red laser: **A Lab Practical Skill**

mλ = d sinθ

d = 0.0125 cm

Solve for x_m:

Plot x_m vs. m!

======================= Fourth Board Section =============================

(3) Limits of vision:

Note: Can't use small angle approximation!!

Return to Setup

	Single Slit: How does a wider slit width affect the diffraction pattern?

	Double Slit: How does a greater separation between slits affect the interferece pattern?


©	St. Lawrence University	Department of Physics