REFLECTION OPTICAL DEVICE

摘要

A reflection optical device having a 2x2 optical switch function or a complete circulation 4-port optical circulator function. The number of parts of the device is small, the reliability of the operation is high, the manufacturing cost is low, and the size can be decreased. In the device, polarized wave separating/multiplexing double refraction means (10), polarized wave rotation means (12), first and second optical path control double refraction means (16, 20), and polarized wave rotation reflective means (22) or optical path change reflective means are arranged in order of mention along the optical axis. First and second linear phase shifters (14, 18) are inserted between the polarized wave rotation means and the first optical path control double refraction means and between the first optical path control double refraction means and the second optical path control double refraction means. An input/output section where four or more optical fibers are arrayed is disposed on the opposite side to the polarized wave rotation reflective means. The polarized wave rotation means is composed of a ±45-degree Faraday rotator (26) and a pair of left and right 1/2 wave plates (27a, 27b) and has an optical switch function performed by changing the polarization direction.