OPTICAL ISOLATOR

摘要

PURPOSE:To provide a condensing effect to an optical isolator and to obtain the optical isolator which is small in size, low in cost and has easy constitution by curing an org. material having a two-color circularly polarizing characteristic in conformity with a replica to form a Fresnel lens and disposing a quarter-wave plate. CONSTITUTION:A cholesteric polymer film is used as the org. material having the two-color circularly polarizing characteristic. A prototype 10 is first manufactured and the replica 11 is obtd. from the prototype by using a UV-curing resin. A cholesteric polymer film 12 is photopolymerized on the replica 11 by which the Fresnel lens consisting of the film 12 is obtd. The linearly polarized light emitted from a semiconductor laser 1 is polarized to the right-hand circularly polarized light by a crystal plate 13 as the quarter-wave plate and is coupled with an optical fiber 14 by passing through the film 12.