| 摘要 |
PURPOSE:To propagate light in only one of two orthogonal polarization modes by making a 1st clad thicker in the direction connecting strain induction parts than in its orthogonal direction. CONSTITUTION:The 1st clad 2 is sectioned in a nearly elliptic shape, major axis is set in an X-axis direction. Then the couple of strain induction parts 14a and 14b are provided in the X-axis direction of a 2nd clad opposite each other across the core 11, and the line connecting those strain induction parts 14a and 14b is set in the major-axis direction of the 1st clad 12. In one of the two orthogonal polarization modes, the propagation constant is larger than the propagation constant of the clads to enable propagation, but in the other polarization mode, the propagation constant is less than or equal to the propagation constant of the clads and there is a wavelength range wherein light is cut off. Consequently, light in only one propagation mode can be propagated in this wavelength range. |
