Optical switches made by nematic liquid crystal switchable mirrors, and apparatus of manufacture

An apparatus for switching a beam of light, comprising:

• a first liquid crystal material transparent to the beam of light;
• a second material transparent to the beam of light, the second material contacting the first liquid crystal material at an interface;
• wherein a temperature of the first liquid crystal material is above a clearing temperature and wherein the first liquid crystal material has a first and a second state, the first state being an isotropic state in the absence of an external field, the second state being a forced nematic state in the presence of said external field, and wherein the index of refraction of the liquid crystal material in the first state matches the index of refraction of the second material, and wherein the index of refraction of the first liquid crystal material in the second state does not match the index of refraction of the second material, whereby the beam of light incident on the interface at an angle greater than the critical angle for total internal reflection is not reflected when the first liquid crystal material is in the first state, and whereby the beam of light incident at the angle on the interface is reflected when the first liquid crystal material is in the second state.