Emission of light from a strip waveguide with periodically varying parameters

A theoretical analysis is made of the problem of the emission of light from a strip waveguide, formed inside a planar waveguide, into the latter waveguide and into the media surrounding it. A calculation is made of the spectral and angular characteristics of the process of emission of light into the planar waveguide. Estimates are obtained of the fraction of the power of light emitted into the planar waveguide. It is shown that a corrugated strip waveguide may be used in integrated-optics devices for demultiplexing of wavelengthdivision multiplexed optical communication channels.