BI-OBLIQUE PROPAGATION ANALYSIS OF SYMMETRICAL AND ASYMMETRIC Y-JUNCTIONS

A novel finite difference beam propagation method (BPM) analysis based upon a bi-oblique coordinate representation is presented. The analysi s yields a computationally efficient algorithm that permits accurate s imulation of a wide variety of structures to be made without staircase approximations. Further, the independent paraxial and wide angle appr oximations, centered upon the direction of optical field propagation i n each branching waveguide, may be incorporated into the algorithm. Th is feature allows a low-order approximation to be used in the algorith m even if one or both of the branching angles is large. The approach h as been applied to both symmetric and asymmetric optical waveguide Y-j unctions and produces results in excellent agreement with those in the literature.