By using a theoretical model to describe coupling between an array of cores, it is shown that a range of monolithic wavelength flattened 1 × 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 × 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 µm and 1.53 µm.
© 1990 Optical Society of America
David B. Mortimore and John W. Arkwright, "Theory and fabrication of wavelength flattened 1 × N single-mode couplers," Appl. Opt. 29, 1814-1818 (1990)