Observation of Wave Packet Dichotomy and Adiabatic Stabilization in an Optical Waveguide

We report on the first experimental observation of wave packet dichotomy and adiabatic stabilization of light in a periodically bent optical waveguide in analogy with similar behavior of atoms in high-frequency strong laser fields.

Figure 1

(a) Microscope image (particular) of the periodically bent waveguide fabricated for the experiments. (b) Schematic of the full waveguide structure. (c) Numerically computed behavior of the average potential $V_{\mathrm{a}\mathrm{v}}(x,y,z)$ at $y=0^{+}$ for parameter values which apply to our structure: $\Delta n=0.0137$, $w=5\mu \mathrm{m}$, $D_x=2.4\mu \mathrm{m}$, $D_y=3.5\mu \mathrm{m}$, $n_s=2.1381$.

Figure 2

(a) Light propagation along the waveguide (top view) and corresponding intensity pattern at the output plane as obtained by numerical simulation of Eq. (1) when the waveguide is probed at $\lambda =1550\mathrm{n}\mathrm{m}$ in its fundamental mode. (b) Intensity pattern of light at the output plane of the waveguide as recorded on the infrared camera. (c) Numerically computed beam power $\mathcal{P}$ (in arbitrary units) versus propagation distance $z$ showing radiation losses. The insets show the 2D intensity patterns at the input and output planes of the waveguide. (d) Experimentally measured intensity profile (in arbitrary units) of the output light beam taken along the horizontal $x$ direction (solid curve) and corresponding profile as obtained by numerical simulations (dotted curve).

Figure 3

Same as Figs. 2a, 2b but when the waveguide is probed at $\lambda =633\mathrm{n}\mathrm{m}$.

Figure 4

Same as Figs. 2a, 2b, 2c but when the waveguide is probed at $\lambda =1064\mathrm{n}\mathrm{m}$. Numerical simulations shown in (a) and (c) are obtained when the fundamental ${\mathrm{T}\mathrm{M}}_{00}$ waveguide mode is excited.

Figure 5

Same as Fig. 4 but numerical simulations in (a) and (c) are now obtained when the first-order ${\mathrm{T}\mathrm{M}}_{10}$ waveguide mode is excited. The experimental measurement in (b) is the same as in Fig. 4b and reported for the sake of comparison with numerical results.