Tunneling of radiation from a single-mode fiber waveguide with a partial cladding

A theoretical study is made of the tunneling of radiation from a single-mode fiber waveguide with a partial cladding. A simple method is proposed for the calculation of the attenuation of the power of the tunneling mode. The results obtained are of fundamental importance in the development and fabrication of fiber-optic directional couplers. The calculated dependences agree with the experimental results obtained by other authors.