SPOT-SIZE CONVERSION OPTICAL WAVEGUIDE

摘要

A spot-size-converting optical waveguide includes a core portion. A first core portion of the core portion has a first straight portion and a first tapered portion. The first straight portion extends in a direction, having width and height that are approximately constant in the direction, and the first tapered portion is continuous with the first straight portion and decreases in width and height toward a termination portion. A second core portion of the core portion has a straight-portion-coating portion, a tapered-portion-coating portion, and a second tapered portion, the straight-portion-coating portion covers the first straight portion, the tapered-portion-coating portion covers the first tapered portion continuously with the straight-portion-coating portion and decreases in width and height along the first tapered portion's shape, and the second tapered portion increases in width and height toward the direction. A refractive index of the second core portion is lower than that of the first core portion.

主权项

1. A spot-size-converting optical waveguide comprising:
a cladding portion; and a core portion disposed in the cladding portion, a refractive index of the core portion being higher than a refractive index of the cladding portion, wherein the core portion includes a first core portion and a second core portion, the first core portion has a first straight portion and a first tapered portion, the first straight portion extends in a predetermined direction and has width and height that are approximately constant in the extension direction, and the first tapered portion is formed to be continuous with the first straight portion and decreases in width and height toward a termination portion, the second core portion has a straight-portion-coating portion, a tapered-portion-coating portion, and a second tapered portion, the straight-portion-coating portion is formed to cover the first straight portion of the first core portion, the tapered-portion-coating portion is formed to cover the first tapered portion of the first core portion continuously with the straight-portion-coating portion and decreases in width and height along a shape of the first tapered portion, and the second tapered portion increases in width and height toward the extension direction, a light-outputting surface is formed at an end portion of the second core portion, and a refractive index of the second core portion is lower than a refractive index of the first core portion.