Select Page
Home 9 Home 9 Circular Obstacle Diffraction: Poisson’s Spot

TEST KEEP CLOSED

THERMAL PROPERTIES OF MATTER

Thermal Expansion

Thermal Conductivity

Circular Obstacle Diffraction: Poisson’s Spot

A laser beam (with spatial filter) diffracts around a circular obstacle (the head of a pin cemented onto a glass slide). A bright spot is observed at the center of the diffraction pattern, confirming the predictions of the wave theory of light, and much to the embarrassment of M. Poisson, a proponent of the (pre-quantum mechanical) corpuscular theory of light.

Circular Obstacle Diffraction: Poisson's Spot