THE PRACTICE STUDIO
Go slowly. Ask why. Make it yours.
PRACTICE / Diffraction gratings
Use the period, then check the envelope
A transmission grating has slit centre spacing d = 2.40 μm and individual slit width a = 0.80 μm. Light is normally incident. The ideal single-slit minima obey a sinθ = pλ, while array maxima obey d sinθ = mλ.
What is the lowest positive array order that coincides with a single-slit minimum, assuming that direction is accessible?
Organize the givens & assumptions
- d = 2.40 μm
- a = 0.80 μm
- p and m are positive integers
Uniform rectangular slits and Fraunhofer diffraction; compare ideal geometric conditions; the specified coincident direction is accessible.
- A
- B
- C
- D
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