A manufacturable technique for implementing low-loss self-imagingwaveguide beamsplitters

A manufacturable technique to implement self-imaging waveguide beamsplitters is proposed and demonstrated. This technique offers low insertion loss and polarization crosstalk, uniform splitting ratios, ease in manufacture, and most importantly application to diverse waveguide material systems. Beamsplitters with splitting ratios that range from 1×2 through 1×17 were fabricated in GaAs-AlGaAs waveguides. For 1×16 splitters integrated with an output ridge waveguide array, the insertion losses in many devices were less than the insertion losses in adjacent straight-through ridge waveguides. The best uniformity spread among the 16 channels was 17.8% and the TE-to-TM and TM-to-TE polarization crosstalks were lower than -25 dB