Nonlinear prism coupling with nonlocality

Abstract

The characteristics of prism coupling of finite-width beams into nonlinear waveguides composed of media with diffusive nonlinearities (thermal, etc.) are calculated by including a one-dimensional diffusion equation for the nonlocal nonlinearity. The resulting longitudinal feedback leads to bistability, and the threshold value for the minimum diffusion length varies inversely with the angular detuning.

Exact and approximate solutions for optical solitary waves in nematic liquid crystals

“…In addition, for low q (q corresponds to the external electric field applied to pre-tilt the molecular director in the (y, z) plane), two stable nematicons of equal amplitudes are supported by the full nematicon equations for two different values of q. The term optical bistability normally refers to the existence of two distinct stable states for a given excitation of the local [70] or nonlocal system [71][72][73], as has been found to occur for solitary waves in saturable Kerr-like media [74][75][76]. Here, the NLC samples exhibit optical bistability in the sense that two nematicons of the same amplitude exist for two different pre-tilts of the molecular director, i.e.…”

All optical switching in azo-polymer planar waveguide

“…Argon ion laser at 488 nm (1.5 mm beam waist) is used to induce the changes in the sample and He-Ne laser light is used to travel across the waveguide in order to probe the photoinduced changes. In order to achieve waveguiding, prism coupling is used [37][38][39][40][41][42]. The HeNe laser was polarized at 45°relative to TE polarization direction then focused by a lens (f= 5 cm) onto the sample via the first prism.…”

All-optical Integrated Nonlinear Devices

“…The simultaneous solution of equations (5) and (6) results in bistability of guided against incident power for an appropriate choice of D and the detuning, as is shown in figure 1 . In particular, the minimum diffusion length D required for optical bistability is a linear function of the initial detuning for a given incident beam waist [32], as shown in figure 2 .…”

“…The scheme of the device is shown in figure 3 for a grating coupler . Since the intensity-dependent index changes because of the strong beam, the weak beam leaving the waveguide experiences an angular deflection according to [28][29][30][31][32][33] AOs(Pg )=ttfl(Pg)/k o cos 0s ,…”