EXCITATION OF A RIDGE-WAVE-GUIDE BY A NOR MALLY INCIDENT LIGHT-BEAM

The problem of excitation of a ridge waveguide by a normally incident light beam is solved. The intermode interaction is shown to have a con siderable influence on the waveguide excitation process. The condition for the optimal excitation of a waveguide with a finite-length gratin g is derived. It is found that destructive interference of the excited modes, resulting In zero efficiency of the coupling of light into a w aveguide, is possible in the case of a semi-infinite grating. The feas ibility of waveguide excitation with a fairly high efficiency (24 %) i s demonstrated.