Arbitrary ratio power splitters using angled silica on silicon multi-mode interference couplers

Planar power splitters with free selection of power splitting ratios have been realized in the form of angled multi-mode interference (MMI) couplers in silica on silicon. Through proper choice of the intersection angle between two MMI couplers, any splitting ratio between 0 and 100% can be selected. The splitting ratios are within /spl plusmn/2 percent of the theoretically calculated values. Fiber-to-fiber losses are 1.1 dB and 18.7 dB for the 100% and 0% outputs, respectively. Excess losses are below 0.5 dB and the polarization dependence is less than 0.1 dB. These planar silica on silicon power splitters are suitable devices both for stand alone with fiber pigtails as well as for integration with other active and passive waveguide components.