OPTICAL ISOLATOR

摘要

PROBLEM TO BE SOLVED: To obtain an optical isolator of a low cost featuring ease of manufacture and a good yield by providing the optical isolator with polarizers consisting of multilayered polymer films which hold a Faraday rotator from both sides of a light incident side and exit side. SOLUTION: The first polarizer 1 and the second polarizer 2 are respectively polarized light plates of a reflection type consisting of the multilayered polymer films and the transmission polarization directions of the respective polarized lights are so set as to attain an angle of 45 deg. with each other. The 45 deg. Faraday rotator 3 consisting of a thick film of GdBiFe garnet and a glass plate 4 of a tapered shape are arranged in the middle of these two polarized light plates. A magnetic field H along the progression direction of light is impressed on the 45 deg. Faraday rotator 3. The two polymer polarizers 1 and 2 forming the angle of 45 deg. in the transmission polarization directions to the linearly polarized light are arranged before and behind the 45 deg. Faraday rotator 3 in the manner described above, by which high reverse direction loss may be obtained.