Laser oscillation in leaky corrugated optical waveguides

Abstract

The characteristics of laser action in leaky corrugated optical waveguides have been investigated using a spectroscopy technique which enables one to determine the guide index and vacuum wavelength differences of the oscillating modes. It is shown that an anomalous spatial beating phenomenon observed in the leaky waves coupled out through the side of the waveguide is due to laser oscillation on a hybrid guided mode where the feedback is provided by backward intermode diffraction. Also discussed are phenomena which can be utilized in multimode devices of this type to restrict the distributed-feedback laser oscillation to narrow-band polarized operation on the lowest-order waveguide mode. © 1973 American Institute of Physics.