Abstract

Resonant optical waveguides (ROWs) are promising period phase-locked arrays¹ that have demonstrated excellent coherent mode control. The periodicity of these arrays can excite radiation modes that may outcouple energy at certain angles with respect to the array surface plane. These angles depend on the order of the excited resonant mode. In this work, the periodicity of these arrays is exploited to cast these devices as distributed feedback (DFB) structures. Coupling to radiation modes causes additional losses and affects the coupling between the elements of the array. A simple dispersion relation for the array modes is derived and the inclusion of a quarter wave phase shift to improve mode discrimination is discussed. The effect of gain and index antiguiding saturation is included. Spatial hole burning effects due to power saturation affects mode discrimination in a negative way² because these holes interface with the normal strong mode confinement, which is a characteristic of these ROW devices in the absence of saturation effects.

© 1992 Optical Society of America