Old and new laboratory experiments on atmospheric optics with a focus
on mirages, rainbows, and halos are presented. Some qualitative demons
trations serve primarily didactical purposes, e.g., by proving the exi
stence of curved Light rays in media with a gradient of the index of r
efraction, by directly visualizing the minimum-deviation curve for rai
nbow paths in water droplets, or by helping to elucidate the ray class
es in hexagons that contribute to a specific halo. In addition, quanti
tative experiments allow a direct comparison of angular positions and
intensities with analytical computations or Monte Carlo simulations of
light scattering from small water droplets or ice hexagons. In partic
ular, the latter can help us to understand complex halo phenomena. (C)
1998 Optical Society of America.