Optics > Interference > Thin Films DCS# 6D30.40

POHL'S RINGS



APPARATUS
 
mounted mica sheet
202-21-D5
mercury arc lamp
214B


DESCRIPTION
Mercury light reflected off the front and back surfaces of a sheet of mica produces an interference pattern on the screen.  Different thickness of mica (0.002" and 0.003") are available to show the effect of thickness on the spacing of the rings.

NOTES
Use an opaque screen or black  cloth to block the transmitted beam of the mercury lamp.