| 摘要 |
<p>PROBLEM TO BE SOLVED: To design an optical isolator in consideration of a light propagation loss.SOLUTION: An optical isolator comprises: a lower clad layer; an optical waveguide layer that is arranged on the lower clad layer; a buffer layer that is arranged on the optical waveguide layer; and a ferromagnetic metal layer that is arranged on part of the buffer layer and forms a plasmon waveguide on an interface with the buffer layer. The buffer layer has thickness that maximizes a performance index determined by a propagation loss of forward light and that of backward light. The performance index increases as the propagation loss of the backward light becomes bigger than that of the forward light, and increases as the sum of the propagation losses of the forward light and the backward light becomes smaller.</p> |
