Losses due to microbending and bending in single-mode two- and three-layer W-type waveguides

Experiments indicated that three-layer W-type single-mode waveguides were less sensitive than two-layer waveguides. A study was made of the spectral dependence of the additional losses due to microbending and also due to regular bending of both types of waveguide. The additional losses in the W-type waveguides depended weakly on the radiation wavelength, in contrast to the two-layer waveguides which were characterized by a strong rise in the losses on increase in the wavelength. Moreover, the three-layer W-type waveguides could be deformed to smaller radii in regular bending than the two-layer waveguides.