Optics > Geometric Optics > Refraction DCS# 6A40.60

SCHLIEREN OPTICAL SYSTEM



APPARATUS
long focal length concave mirror
202-10-A
white LED with pinhole mask
202-21-F5
rainbow filters
202-21-F5
DC power supply for the LED
202-08-D
razor blade, mounted
202-21-C5
video or document camera
202-09-C4
soldering iron, candle, or other heat source
202-02-C1


DESCRIPTION
A concave mirror is used to image a point source of light on a razor's edge.  Any nonuniformities in the refractive index of the air in the light path can deflect the light so that it reaches the camera and appears as a bright region or is blocked by the blade and appears dark.  Convection currents from your hand or a candle cause variations in the refractive index of the air which appear as variations in light intensity.

NOTES