Abstract

Microwave and optical phased arrays, fiber optic (FO) networks, FO sensor arrays, wavelength multiplexers/demultiplexers, and signal processing systems require both single-mode and multimode fiber distributive couplers with low excess loss as well as low loss deviation. Various techniques, including biconical fusion, channel waveguide, and holographic distribution, have been experimentally tried in the construction of 1 × N couplers with N ≤ 100. However, these conventional techniques have shortcomings of poor reproducibility, high insertion loss, and large loss deviation. To improve fabrication yield, reduce loss, and Increase the number of output ports, a new construction method employing a graded index (GRIN) lens was developed for both single-mode and multimode couplers. The pictorial concept of a 1 × N coupler with N over 100 employing a GRIN lens is shown in Fig. 1.

© 1990 Optical Society of America