Single Mode Photonic Circuit Architecture and a New Optical Splitter Design Based on Parallel Waveguide Mode Conversion

Abstract

The new single mode circuit (SMC) architecture is invented for photonic integrated circuits (PIC). This architecture allows using multimode waveguides or structures to construct a single mode operated PIC. The multimode sections used in such SMC based PIC possess strong lateral confinement so that the PIC can have high circuit density and high optical performance at the same time. A parallel mode converter structure is also invented here. Based on this parallel mode converter, a low loss optical splitter can be constructed for high index contrast waveguide system.

1 . Single mode photonic circuit architecture for planar lightwave circuits, the said single mode photonic circuit architecture uses multiple pairs of multimode waveguide section and mode filter; the said multimode waveguide is the ridge waveguide with the lateral index contrast greater than the single mode ridge waveguide at the same material system, so that small bend radius can be used; the said ridge waveguide with larger lateral index contrast is realized by deep etch into the silicon in a silicon-on-insulator system. 
     
     
         2 . The single mode photonic circuit architecture for planar lightwave circuits recited in  claim 1  wherein multiple pairs of multimode waveguide section and mode filter are connected in series or in parallel. 
     
     
         3 . The single mode photonic circuit architecture recited in  claim 2  wherein the mode filter structure is the combination of the waveguide lens and waveguide pin hole, the said waveguide pin hole removes the potential high order mode excitement at the waveguide lens section to ensure the single mode operation of the following planar lightwave circuits. 
     
     
         4 . The single mode photonic circuit architecture recited in  claim 1  wherein the mode filter structure is the combination of the waveguide lens and waveguide pin hole, the said waveguide pin hole removes the potential high order mode excitement at the waveguide lens section to ensure the single mode operation of the following planar lightwave circuits.