1. Two light pulses are emitted simultaneously from a source. Both pulses
travel to a detector, but one first passes through 6.20 m of ice (n = 1.3).
(a) Determine the optical path difference for the two pulses.
(b) Determine the difference in the pulses' times of arrival at the detector.
(c) Determine the phase difference in radians for the pulses at the detector, in terms of the wavelength and frequency.
2. A possible means for making an airplane invisible to radar is to coat the plane with an antireflective polymer. If radar waves have a wavelength of 3.00 cm and the index of refraction of the polymer is n=1.50, how thick would you make the coating?
3. You observe that a light source shown through a diffraction
grating of 3660 slits per cm produces three discrete 1st order
spectral lines at angles in degrees of 10.09, 13.71, and 14.77.
(a) What are the wavelengths of the light?
(b) At what angles are these lines found in the 2nd order spectrum?
4. A double-slit diffraction pattern is formed using mercury green light at 546.1 nm. Each slit has a width of 0.100mm. The pattern reveals that the 4th-order interference maxima are mising from the pattern. What is the slit separation?
Answer Key
1. (a) 1.86m (b) 6.2ns (c) 11.7/λ ; 3.9 x 10-8ν
2. 0.5cm
3. (a) 479nm, 647nm, 695nm (b) 20.5, 28.3, 30.6 degrees
4. 0.400mm
Last updated October 5, 2009