Symmetric three-branch optical power divider with a coupling cap

Proposed is a new fork-type three-branch optical power divider consisting of two different dielectric materials. The structure is composed of a symmetric Y-branch waveguide with a phase front retarder and a center branch located a coupling gap apart. The present power divider suffers minimum radiation losses as compared to previously reported fork-type three-branch devices consisting of two dielectric materials. Numerical simulations are carried out with a finite difference beam propagation analysis for representative three different sets of significant structural parameters as the refractive index and waveguide width. Numerical results also contain the power dividing characteristics for the case where sharp wedges of index distribution are blunted.