Chapter 24 & 25

Geometrical Optics &
Physical Optics


Diffraction Gratings


Principal Maxima:


where d is the separation between lines and


Example 25

Find the slit spacing necessary for 450 nm light to have a first order (m = 1) principal maximum at 15°.





Example 26

When 546 nm light passes through a particular diffraction grating, a second order principal maximum is observed at an angle of 16°. How many lines per centimeter does this grating have?




Calculate d:

Convert to centimeters:

Find the inverse:




The End