Fiber circular polarizer.
A fiber circular polarizer, composed of a metal-coated fiber polarizer and a lambda/4 platelet fabricated on a birefringent fiber, has been demonstrated. The lambda/4 platelet was made by cutting a birefringent fiber to an appropriate length. The device structure was designed by stress analysis simulation using a finite element method to set the angle theta = pi/4 between the fiber polarizer axis and the birefringent fiber major axis. The 17.6-dB maximum extinction ratio was obtained when the left- and right-circularly polarized light was launched into the device. It is assumed that such a fiber circular polarizer will operate as a quasi-isolator, because the light reflected from the output, the main factor backing the light source, is eliminated.
Hosaka
T
T
NTT Ibaraki Electrical Communication Laboratory, Tokai, Ibaraki-ken 319-11, Japan.
Okamoto
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K
Edahiro
T
T