The Malus' Law calculator computes the intensity of light based on the initial intensity and the angle between the light's initial polarization direction and the axis of the polarizer.
INSTRUCTIONS: Enter the following:
- (I0) Initial Intensity
- (θ) angle the light's initial polarization direction and the axis of the polarizer
Intensity (I): The calculator returns the intensity in Watts per square meter.
The Math / Science
Malus' Law says that when a perfect polarizer is placed in a polarized beam of light, the intensity, I, of the light that passes through is given by the following equation:
I = I0 • cos²θi
where:
- I = Intensity of light based on Malus' Law
- I0 = Initial Intensity in W/m2
- θi = Angle between the light's initial polarization direction and the axis of the polarizer
References
The definition and formula are from Wikipedia (https://en.wikipedia.org/wiki/Polarizer).
