Week 12
Read: Measuring light's wavelength (Chap. 20), Films, bubbles and rainbows (Chap. 21).
PHY 202 Lecture: Wave optics
PHY 202 Lecture: Wave optics
HW:
Lab: Measuring hair diameter (Ex. 20.2). In this lab, we will use a Helium-Neon laser beam to illuminate a hair pressed between two microscope slides. By measuring the spacing of the interference fringes thus produced, we can determine the diameter of the hair. In the course of this experiment, you will need to measure and plot the angle, theta_n, at which the nth interference fringe occurs. Is sin(theta_n) proportional to n? If so, what is the slope of this plot? How can you determine the hair diameter from these measurements?
Chapter 18 (3 videos on Newton's Optics):
Chapter 20 (3 videos on Young's Lectures on Light):
Chapter 21 (2 more videos on Young's lectures on light):
Interesting related web content: The Rosetta stone, which Thomas Young helped translate in the 18th century after it was found by Napoleon's invading armies, now resides in the British Museum; Egypt still wants it back.
- Fiber interference fringes (Ex. 20.1)
- Two-slit interference pattern (Ex. 20.3)
- PHY 202: Diffraction gratings (Ex. 20.4)
- Soap film interference (Ex. 21.1)
- Optical path length (Ex. 21.2).
- Thin film practice problem: A layer of iron oxide (refractive index 2.9) forms on the surface of a polished iron plate. When this layer is illuminated from above with white light, approximately how thick must the layer be in order for it to appear blueish in color?
Lab: Measuring hair diameter (Ex. 20.2). In this lab, we will use a Helium-Neon laser beam to illuminate a hair pressed between two microscope slides. By measuring the spacing of the interference fringes thus produced, we can determine the diameter of the hair. In the course of this experiment, you will need to measure and plot the angle, theta_n, at which the nth interference fringe occurs. Is sin(theta_n) proportional to n? If so, what is the slope of this plot? How can you determine the hair diameter from these measurements?
Chapter 18 (3 videos on Newton's Optics):
Chapter 20 (3 videos on Young's Lectures on Light):
Chapter 21 (2 more videos on Young's lectures on light):
Interesting related web content: The Rosetta stone, which Thomas Young helped translate in the 18th century after it was found by Napoleon's invading armies, now resides in the British Museum; Egypt still wants it back.