12 FIG. 2: (color online) Behavior of fractional light power trapped in channel waveguides W$_{1}$ (blue curve) and W$_{2}$ (green curve) versus propagation distance in a L = 6-cm-long structure and corresponding transverse light intensity distri- butions at the input ( z = 0) and output ( z = 6 cm) planes, as obtained by numerical simulations of the wave equation (1) for two different excitation conditions. In (a) waveguide W$_{1}$ is excited in its fundamental mode, leading to fractional decay. In (b) the trapped state is excited, corresponding to full suppression of light leakage into the slab S. Parameter values used in the simulations are: λ = 980 nm, n s = 1 . 52, Δ n S = 0 . 0049, Δ n g = 0 . 01, d = 9 µ m, r c = 2 µ m, and a = 4 µ m. 0 2 4 6 0.2 0.4 0.6 0.8 1 0 50 0 50 0 50 0 2 4 6 0.2 0.4 0.6 0.8 1 zGLYPH<.notdef>(cm) yGLYPH<.notdef>( m) GLYPH<c109> xGLYPH<.notdef>( m) GLYPH<c109> xGLYPH<.notdef>( m) GLYPH<c109> FractionalGLYPH<.notdef>power 0 50 0 50 xGLYPH<.notdef>( m) GLYPH<c109> 0 50 0 50 yGLYPH<.notdef>( m) GLYPH<c109> xGLYPH<.notdef>( m) GLYPH<c109> zGLYPH<.notdef>(cm) FractionalGLYPH<.notdef>power z=0 z=6GLYPH<.notdef>cm z=0 z=6GLYPH<.notdef>cm (a) (b)