RADIATION LOSSES OF TAPERED DIELECTRIC WAVE-GUIDES - A FINITE-DIFFERENCE ANALYSIS WITH RIDGE-WAVE-GUIDE APPLICATIONS

The finite-difference third-order simplified wave equation method is u sed to study the radiation losses of optical waveguides;vith step (abr upt) and parabolic taper's, including the radiation losses of the tape red ridge waveguides used as electrooptic phase modulators for tuning the frequencies of infrared lasers. The radiation losses of the parabo lic taper given by Burns et al. is found to be under 5%. The results o f a step taper are compared with Marcuse's; and found to be in good ag reement. The numerical results are also compared with those from the c oupled-wave equations used by Sporloder and Unger.