Abstract

Silica-based planar lightwave circuits on silicon (Si) substrates have become important in optical communication systems [1]. The planar ring resonator, which has been used in frequency-stabilized light sources, is one such device. Recently, a finesse-variable ring resonator was reported [2]. This was realized by integrating a Mach-Zehnder waveguide coupler whose coupling ratio was tunable. However, the finesse is limited because the propagation loss in the resonator can not be compensated for with the device.

© 1993 Optical Society of America