| 摘要 |
PROBLEM TO BE SOLVED: To provide a polarization-independent optical isolator excellent in reverse direction loss characteristics.SOLUTION: A polarization-independent optical isolator 100 is configured such that first and second Faraday rotators (20a, 20b) intervene between first and second birefringent elements (11a-12a) and between third and fourth birefringent elements (11a-12a), the birefringent elements arranged in a fore-and-aft point symmetry, in a fore-and-aft direction used as a z-axis. The first and second birefringent elements and the third and fourth birefringent elements have optical axes (13a, 14a and 13b, 14b) in an xy plane that are inclined at 45° to each other about the z-axis. The angles of inclined planes (31a, 34a, and 31b, 34b) in a yz plane are θand θ, respectively, and the first and second Faraday rotators have Faraday rotation directions opposite to each other. The second and third birefringent elements are arranged facing each other so that the inclination directions are 180° with respect to each other and so that optical axes of each intersects with each other at 90° about the z-axis. The inclination angles θand θare different from each other.SELECTED DRAWING: Figure 5 |
