THEORY AND FABRICATION OF WAVELENGTH FLATTENED 1XN SINGLE-MODE COUPLERS

By using a theoretical model to describe coupling between an array of cores, it is shown that a range of monolithic wavelength flattened 1 X N couplers may be fabricated. Graphs of coupled power with coupling length are shown and the procedure for obtaining wavelength flattened devices is discussed for values of N ranging from 2 to 7. The fabrication and performance of a 1 X 7 coupler is described. The device has low excess loss (<0.3 dB) together with good coupling uniformity of <1% standard deviation at both 1.3 ym and 1.53 μm. © 1990 Optical Society of America.