DESIGN OF 3-DB INTEGRATED OPTICAL COUPLERS IN ASYMMETRIC BRANCHING WAVE-GUIDES

We present here a study of phase-front accelerator (PFA) effects on the operation of integrated optical asymmetrical Y-branch waveguides. The use of a PFA sector and the careful design of waveguide parameters will give equal power division between the two asymmetric branch outputs under nonadiabatic conditions (i.e., power-dividing behaviour). In addition, the transmission loss is significantly reduced in such a design structure when compared to conventional Y-branch waveguides, particularly when the half-branching angle is larger than 1-degrees.