Patent ID: 9547129
Date: 2017-01-17
CPC Classifications: G02B

Claim:
1. An apparatus for converting fiber mode to waveguide mode, the apparatus comprising: a silicon substrate member; a first dielectric member having an elongated body, part of the elongated body from a back end overlying the silicon substrate member and a remaining part of the elongated body up to a front end being separated from the silicon substrate member by a second dielectric material at an under region; a waveguide including a segment from the back end to a tail end formed on the first dielectric member at least partially overlying the remaining part of the elongated body, the segment being buried in a cladding overlying entirely the first dielectric member below from the front end to the back end while being covered by the second dielectric material from both sides and top, wherein the cladding has a refractive index that is less than the waveguide but includes an index-graded section formed at least over the segment with decreasing index from the tail end toward the back end, wherein the index-graded section comprises patterned etching slots having a depth partially into the cladding and having increasing widths and increasing slot-slot spacing from a location near the tail end of the segment of the waveguide to the back end of the segment of the waveguide.