| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical multiplexer/demultiplexer having structure by which a manufacture tolerance required for realizing the improvement of a transmission wavelength characteristics is relaxed. SOLUTION: A free propagation region (160) for improving the transmission wavelength characteristic is provided between an input waveguide (110) and a first slab waveguide (120). The free propagation region (160) is provided with a first part (161) whose width is increased from the input waveguide (110) toward the first slab waveguide (120) and a second part (162) which has the width larger than that of he input waveguide (110), the distribution of electric field intensity of light which advances from the input waveguide (110) to the first slab waveguide (120) is widened once by the first part (161), but the widening is inversely limited by the second part (162). Thus, the change of the distribution of electric field intensity is less liable to the change of a waveguide width, and consequently required precision for fine working is relaxed.
|
