Optics > Interference > Two Source Interference DCS# 6D10.11

DOUBLE SLIT PATTERN


APPARATUS
 
CAL sheet aka Cornell slitfilm demonstrator 202-21-B5
laser or laser pointer
202-21-B6


DESCRIPTION Shine the laser light through the slits on the sheet to project interference patterns on the screen.  The sheet has single slits of various widths, double slits of various widths and separations, and sets of different numbers of multiple slits.

Green (532 nm) and red (650 nm) laser pointers can be used to show the dependence of diffraction angle on wavelength.
NOTES
CAL sheet
Refer to this image for slit widths and spacings. 
Beside each element:
top digit = number of lines, 
middle digit = width in points before 8x reduction,       
bottom digit = spacing in points between lines
(one point = 0.013837 inch = 0.3523 mm).
The distance in millimeters between the slits is shown under the patterns.

We also have a diffraction mosaic slide (202-21-B5) with four double slits and three multiple-slit arrays.  The double slit separations are 45, 58, 75 and 100 µm. The slit width for the latter is twice that of the others.  The three gratings are 25, 50 and 100 lines/mm.