Abstract

Er-doped glass planar waveguides [1-3] have been investigated with a view to constructing optical devices for advanced optical communication systems such as ultra high speed transmission systems [4], Several devices have been demonstrated using waveguides made with various materials and using waveguide circuit elements such as directional couplers and Bragg reflectors. These devices, wholly constructed with Er-doped waveguides, include an amplifier equipped with a signal/pump wavelength division multiplexing (WDM) coupler [5] and a single-longitudinal-mode waveguide laser [6]. However, the function, circuit configuration, and scale of integration of the Er-doped waveguide devices were limited since the waveguides exhibit large Er³⁺ absorption loss at signal wavelengths in the 1.5 μm telecommunication window when they were unexcited. Therefore, there is a strong need to integrate Er-doped and undoped waveguides on a substrate.

© 1996 Optical Society of America