Bent taper with varying widths for an optical waveguide
View Patent ↗A SOI bent taper structure is used as a mode convertor. By tuning the widths of the bent taper and the bend angles, almost lossless mode conversion is realized between TE0 and TE1 in a silicon waveguide. The simulated loss is <0.05 dB across C-band. This bent taper can be combined with bi-layer TM0-TE1 rotator to reach very high efficient TM0-TE0 polarization rotator. An ultra-compact (9 μm) bi-layer TM0-TE1 taper based on particle swarm optimization is demonstrated. The entire TM0-TE0 rotator has a loss <0.25 dB and polarization extinction ratio >25 dB, worst-case across the C-band.
1. An optical waveguide component, comprising:
a bent taper having an input port and an output port, said bent taper having a length, said bent taper having at least one bent waveguide segment, said bent taper having a varying waveguide width at at least two different locations along said length;
wherein said bent taper has a shape similar to the letter “S,” a center radius R 0 , and an offset dy measured as a lateral distance between said input and output ports, said bent taper configured to be represented as a plurality of segments of angular measure d θ .
2. The optical waveguide component of claim 1 , wherein each of said plurality of segments of angular measure d θ has the same angular measure.
3. The optical waveguide component of claim 1 , wherein at least two of said plurality of segments of angular measure d θ have different angular measure.
4. The optical waveguide component of claim 1 , wherein said bent taper is configured as a mode converter.
5. The optical waveguide component of claim 1 , further comprising a bi-layer taper comprising: an input port, an output port, a length, and a plurality of widths w_ja, w_jb at different locations j along said length, where ja and jb are ordinal numbers for first and second layers, respectively;
wherein said input port of said bent taper is in optical communication with the output port of a bi-layer taper.
6. The optical waveguide component of claim 5 , wherein said bi-layer taper and said bent taper are configured as a polarization rotator.
7. The optical waveguide component of claim 6 , wherein said bi-layer taper is configured to provide a TM0-TE1 mode conversion; and wherein said bent taper is configured to provide TE1-TE0 mode conversion.
8. The optical waveguide component of claim 1 , further comprising a mode conversion element configured to convert a TM0 mode to an intermediate mode, and wherein said bent taper is configured to convert said intermediate mode to a TE0 mode.
9. The optical waveguide component of claim 1 , configured to operate at a wavelength within the range of a selected one of an O-Band, an E-band, a C-band, an L-Band, an S-Band and a U-band.
10. An optical waveguide component, comprising:
a bent taper having an input port and an output port, said bent taper having a length, said bent taper having at least one bent waveguide segment, said bent taper having a varying waveguide width at at least two different locations along said length; and
a bi-layer taper comprising: an input port, an output port, a length, and a plurality of widths w_ja, w_jb at different locations j along said length, where ja and jb are ordinal numbers for first and second layers, respectively;
wherein said input port of said bent taper is in optical communication with the output port of a bi-layer taper.
11. The optical waveguide component of claim 10 , wherein said bent taper has a shape similar to the letter “S”, a center radius R 0 , and an offset dy measured as a lateral distance between said input and output ports, said bent taper configured to be represented as a plurality of segments of angular measure d θ .
12. The optical waveguide component of claim 11 , wherein each of said plurality of segments of angular measure d θ has the same angular measure.
13. The optical waveguide component of claim 11 , wherein at least two of said plurality of segments of angular measure d θ have different angular measure.
14. The optical waveguide component of claim 10 , wherein said bi-layer taper and said bent taper are configured as a polarization rotator.
15. The optical waveguide component of claim 14 , wherein said bi-layer taper is configured to provide a TM0-TE1 mode conversion; and wherein said bent taper is configured to provide TE1-TE0 mode conversion.