[问答题]
A beam of light enters the end of
q , c;wb f:;s0e*1aqrrdv6 lxy an optic fiber as
.4xi.h abm,tb:fi6g a shown in (Fig. Below). Show that we can guarantee total internal reflection at the side sur
ba.x: b4mghi.6, aft iface of the material (at point a), if the index of refraction is greater than about 1.42. In other words, regardless of the angle the light beam reflects back into the material at point a.
