Buried rib passive waveguide Y junctions with sharp vertex on InP

A technique is presented for fabricating intersecting waveguides with a sharp junction vertex. This technique was demonstrated by fabricating buried rib waveguide Y branches on InP with a junction vertex width of about 1/8 mu m. These Y branches had lower loss than the regular blunt Y branches but suffered from a dissimilar splitting coefficient between the two arms. This technique may also be useful for fabricating other waveguide elements such as crossed waveguides, zero gap directional couplers, and optical switches. A comparison with theoretical calculations is also given.<
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