zoo tib yam teeb

Thaum birefringence tshwm sim thaum lub teeb propagates nyob rau hauv ib tug uniaxial siv lead ua, ib tug ntawm ob lub refracted beam yeej ib txwm ua raws li txoj cai ib txwm refraction, thiab lub beam no hu ua lub teeb zoo tib yam.