Quick Answer: The Couple of Polarizing Filters is a pair of polarising filters for showing how light intensity changes as one filter is rotated against the other. Crossing the two filters gives extinction of the transmitted light.
Last updated: October 2026
Key Features
2 polarising filters
Shows transmission, extinction and analyser rotation
Introduces Malus’ Law and linearly polarised light
Used with light sources, filter holders, optical benches and screens
Technical Specifications
Specification
Value
Quantity
2 polarizing filters
Primary use
Demonstration of light polarisation, transmission, extinction and analyser rotation
One filter acts as the polariser and the second as the analyser: rotating the analyser makes the light brighten and dim, and at the crossed position it is almost blocked. Students relate the brightness at different angles to Malus’ Law and compare polarised with unpolarised light.
Frequently Asked Questions
What happens when the two filters are crossed?
The transmitted light reaches extinction, showing that the first filter has polarised the light and the second blocks that direction.
