| 摘要 |
PROBLEM TO BE SOLVED: To make realizable a multi-functional optical coupling in an optical coupler, which can constitute an excitation module used for both forward and backward excitation types, and an optical circulator having a function of selecting wavelength and a function of separating or composing polarizations. SOLUTION: Ports P<SB>1</SB>and P<SB>2</SB>are disposed at one end whereas ports P<SB>3</SB>and P<SB>4</SB>are disposed at the other end. Between them, a birefringent crystal panel 2, a compound wavelength plate 3a, a Faraday rotor 3b, a birefringent crystal plate 4, a second polarization rotating means 5, and a filter 5 are disposed in that order. An optical path is determined by turning the direction of the polarization of a luminous flux. The luminous flux is reflected or transmitted by a filter 6 according to its wavelength. Thereby, a circulation optical path for conveying the luminous flux in one direction, a selection optical path, a forward travelling optical path, and a backward travelling optical path are formed between the ports. COPYRIGHT: (C)2005,JPO&NCIPI |
