An integrated optical TE-TM mode splitter

A hybrid technology developed for the deposition in planar waveguides of a multilayer which controls the guided optical power by interference has been tested using a TE-TM mode splitter as an example. The preparation of waveguides which exhibit good edge properties, the deposition of the multilayer and the mutual alignment of the waveguides by better than λ/5 are described. The ratio of the transmitted TE power to the reflected TM power has been measured to be 0.9±0.1, which agrees well with the 1.0 yielded by theory. Distortion due to mode conversion, TE reflectance and TM transmittance is of the order of 1%.