Patent ID: 7483088

Claim:
A tunable terahertz (THz) wavelength selector device includes: a fixed phase retarder which includes a homogeneous aligned first liquid crystal cell, a pair of opposite magnet slabs, and a first clamp to fix the first liquid crystal cell and the class of magnet slabs, wherein the first liquid crystal cell is set in between the pair of magnet slabs, used for providing fixed phase retardation used in the terahertz wavelength, utilizing orientation of liquid crystal molecule in the first liquid crystal cell; a tunable phase retarder which includes a homeotropic aligned second liquid crystal cell, a magnet, and a second clamp to fix the second liquid crystal cell and the magnet, wherein the second clamp can rotate the magnet so as to provide variable magnetic field to change the orientation of liquid crystal molecule in the second liquid crystal cell, used for providing positive or negative phase retardation relative to the fixed phase retarder of the tera hertz wavelength; and a pair of linear polarizers, separately set adjacent to the deployed fixed phase retarder and tunable phase on both sides, used for attenuating the class of phase retardation which are not integer multiple of π in the terahertz wavelength, wherein π is the circular constant.