| 摘要 |
<p>PROBLEM TO BE SOLVED: To provide a non-linear optical waveguide element capable of being easily connected to the outside, increasing the photoelectric field of a reference waveguide mode in a non-linear optical waveguide part, and attaining a very fast optical switching high in extinction ratio without any inter-bit interference. SOLUTION: The non-linear waveguide element utilizing the inter-sub-band transition of a nitride semiconductor quantum well is provided with light input parts 2, 3 having a large spot diameter in a waveguide mode, a light output part 4, a non-linear waveguide part 9 having a small spot diameter in the waveguide mode, spot size conversion parts 5, 10 arranged between the light input/output parts 2 to 4 and the waveguide part 9 and capable of converting the spot size by changing the width of an optical waveguide layer, and a waveguide mode sepection part 8 arranged between the spot size conversion part 5 arranged on the side of the light input parts 2, 3 and the non-linear optical waveguide part 9, consisting of an optical waveguide layer bending part 6, a clad layer narrowing part 7 and an absorption area 15 and capable of selecting only a reference mode.</p> |
