Method for manufacturing an optical device

A method for the fabrication of a spot-size converter, comprising the steps of:

• a) forming a first waveguide layer, a first cladding layer, a second waveguide layer and a second cladding layer on a semiconductor substrate, sequentially;
• b) forming a mask layer on the second cladding layer and patterning the mask layer into a predetermined configuration in such a way that the predetermined configuration has a taper portion at its both distal ends and a pair of strain distributed pads;
• c) etching the second cladding layer and the second waveguide layer by using the patterned mask layer as an etching mask;
• and
• d) removing the patterned mask layer and subsequently removing portions of the second cladding layer and the second waveguide layer corresponding to the strain distributed pads, thereby obtaining a tapered waveguide on top of the first cladding layer.

An optical device, which is manufactured by the following steps of:

• forming a waveguide layer on a semiconductor substrate;
• b) forming a mask layer and patterning the mask layer into a predetermined configuration in such a way that the predetermined configuration has a taper portion at its both distal ends and a pair of strain distributed pads;
• c) etching the waveguide layer using the patterned mask layer as an etching mask;
• and
• d) removing the patterned mask layer and subsequently removing portions of the waveguide layer corresponding to the strain distributed pads, thereby obtaining a tapered waveguide.

An optical device, which is manufactured by the following steps of:

• a) forming a first waveguide layer, a first cladding layer, a second waveguide layer and a second cladding layer on a semiconductor substrate, sequentially;
• b) forming a mask layer on the second cladding layer and patterning the mask layer into a predetermined configuration in such a way that the predetermined configuration has a taper portion at its both distal ends and a pair of strain distributed pads;
• c) etching the second cladding layer and the second waveguide layer by using the patterned mask layer as an etching mask;
• and
• d) removing the patterned mask layer and subsequently removing portions of the second cladding layer and the second waveguide layer corresponding to the strain distributed pads, thereby obtaining a tapered waveguide on top of the first cladding layer.