Christian E. Rüter

Observation of staggered surface solitary waves in one-dimensional waveguide arrays.

The observation of nonlinear staggered surface states at the interface between a substrate and a one-dimensional self-defocusing nonlinear waveguide array is reported. Launching of staggered input beams of different power in the first channel of the array results in formation of localized structures in different channels. Our experimental results are confirmed numerically.

Optical channel waveguides in Nd:YVO4 crystal produced by O+ ion implantation

In this letter, we report on optical channel waveguides in Nd:YVO4 crystals produced by photographic masking and following direct O+ ion implantation at 3.0MeV. Annealing treatments of the samples are performed to improve the waveguide stability and to reduce losses. An increase of the ordinary refractive index induced by the implantation is believed to be responsible for waveguide formation. Quasi-TM guided modes are observed, while no quasi-TE ones are detected. The optical damping coefficients are of 0.43, 0.63, and 0.54cm−1 for channel waveguides with widths of 4, 5, and 6μm, respectively. The result of modal analysis is in agreement with the experimental data.

Ridge waveguide lasers in Nd:YAG crystals produced by combining swift heavy ion irradiation and precise diamond blade dicing

Ridge waveguides have been fabricated in Nd:YAG crystals by using ion irradiation and precise diamond blade dicing. Continuous-wave lasers at ~1064 nm have been realized in the ridge waveguides through optical pumping at 808 nm at room temperature. The ridge guiding structure shows superior lasing performance with respect to the planar counterpart with a slope efficiency of 43% and a maximum output power of 84 mW.

Optical modes at the interface between two dissimilar discrete meta-materials

We have studied theoretically and experimentally the properties of optical surface modes at the hetero-interface between two meta-materials. These meta-materials consisted of two 1D AlGaAs waveguide arrays with different band structures.

Observation of modulational instability in discrete media with self-defocusing nonlinearity

We report what we believe is the first observation of modulation instability in the anomalous-diffraction regions of a photonic lattice. The experiments were carried out in a 1D waveguide array fabricated in a lithium niobate crystal displaying the photovoltaic self-defocusing nonlinearity, and our results are confirmed numerically by simulating the nonlinear beam propagation.

Low loss ridge waveguides in lithium niobate thin films by optical grade diamond blade dicing.

We report on the fabrication and characterization of ridge waveguides in lithium niobate thin films by diamond blade dicing. The lithium niobate thin films with a thickness of 1 µm were fabricated by bonding a He-implanted lithium niobate wafer to a SiO(2)-coated lithium niobate wafer and crystal ion slicing. Propagation losses of 1.2 dB/cm for TE and 2.8 dB/cm for TM polarization were measured at 1550 nm for a 9.28 mm long and 2.1 µm wide waveguide using the Fabry-Perot method.

Beam interactions in one-dimensional saturable waveguide arrays.

The interaction between two parallel beams in one-dimensional discrete saturable systems has been investigated using lithium niobate nonlinear waveguide arrays. When the beams are separated by one channel and in phase it is possible to observe soliton fusion at low power levels. This result is confirmed numerically. By increasing the power, solitonlike propagation of weakly coupled beams occurs. When the beams are out-of-phase the most interesting numerically obtained result is the existence of oscillations which resemble the recently discovered Tamm oscillations.

Dark and bright blocker soliton interaction in defocusing waveguide arrays

We experimentally demonstrate the interaction of an optical probe beam with both bright and dark blocker solitons formed with low optical light power in a saturable defocusing waveguide array in photorefractive lithium niobate. A phase insensitive interaction of the beams is achieved by means of counterpropagating light waves. Partial and full reflection (blocking) of the probe beam on the positive or negative light-induced defect is obtained, respectively, in good agreement with numerical simulations.

Revisiting the

In this paper, we revisit one of the prototypical -symmetric oligomers, namely the trimer. We find all the relevant branches of ?regular? solutions and analyze the bifurcations and instabilities thereof. Our work generalizes the formulation that was recently proposed in the case of dimers for the so-called ?ghost states? of trimers, which we also identify and connect to symmetry-breaking bifurcations from the regular states. We also examine the dynamics of unstable trimers, as well as those of the ghost states in the parametric regime where the latter are found to exist. Finally, we present the current state-of-the-art for optical experiments in -symmetric trimers, as well as experimental results in a gain?loss?gain three channel waveguide structure.

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We experimentally investigate the interaction of counterpropagating discrete solitons in a one-dimensional waveguide array in photorefractive lithium niobate. While for low input powers only weak interaction and formation of counterpropagating vector solitons are observed, for higher input powers a growing instability results in discrete lateral shifting of the formed discrete solitons. Numerical modeling shows the existence of three different regimes: stable propagation of vector solitons at low power, instability for intermediate power levels leading to discrete shifting of the two discrete solitons, and an irregular temporal dynamic behavior of the two beams for high input power.