Physics · Ch 6 — Optics
Uses of Polaroids
Uses of Polaroids
Everyday and technological uses of polaroids: (1) goggles and cameras, to reduce glare; (2) three-dimensional motion pictures (holography-related viewing systems); (3) improving the contrast of old, faded oil paintings; (4) optical stress analysis; (5) window glasses that can control the intensity of incoming light; (6) reading and writing compact discs (CDs), where a polarised laser beam acts as the 'needle'; and (7 …
What this figure shows. Unpolarised sunlight reflects off a horizontal surface (such as a road or water), and because reflection at typical viewing angles partially polarises light in the horizontal plane, the glare an observer would ordinarily see is strongly horizontally polarised. Polaroid sunglasses are made with their transmission axis oriented vertically, so this horizontally polarised glare component is largely blocked while ordinary, more vertically-oriented direct light from objects is transmitted much less reduced -- greatly cutting glare w …