Array theorem and convolutions Derive array theorem from convolution theorem

Review: Sketch the diffraction pattern of this rectangular slit I got it mostly right I got it mostly wrong but I tried

The E-field at the screen due to one slit is (centered at the origin) Find and sketch the E-field at the screen due to due slits centered at y = ±h/2. I got it mostly right I got it mostly wrong but I tried

Diffraction of the light from a distant flashlight viewed through a black umbrella fabric.

2-slit Fraun. diffraction pattern

N-slits diffraction features How many minor peaks are between the major peaks?

http://optics.byu.edu/animation/fraunhof.mov

N-slits, grooves,mirror-strips  diffraction grating major peaks occur when: minor peaks occur when:

N-slits, grooves,mirror-strips  diffraction grating Ratio of major to minor peak in I: a) N b) N2 b) N1/2 Width of major peak decreases as what power of N? a) 1/N b) 1/N2 b) 1/N1/2

Diffraction grating orders

Diffraction grating orders

Reflective gratings are “blazed” Typical grating for visible to UV light: 1000-2000 grooves/mm, 10 cm wide105 lines. Reflective gratings most common: lines cut in glass, replicated onto plastic blanks, coated with metal (aluminum)

Modern methods Blazed gratings put more light into a nonzero order

Resolving power of a grating How much must l change so peak moves by half its width?

Spectrometer Put slits at f from mirrors. Grating in center