Simple physics of quadratic spatial solitons

Spatial solitons in quadratically nonlinear media result from the interplay of parametric gain, diffraction and cascading phase shift. Their main features are well understood in mathematical terms, and several experiments have been successfully carried out which demonstrate their observability and most important properties. Here we provide an intuitive interpretation of some of the underlying physics, outlining the processes that govern their excitation, propagation and interaction forces

All-optical multiphoton absorption figures of merit: Polydiacetylene poly (bis para-toluene sulfonate) of 2,4-hexadiyne-1,6 diol

The all-optical switching figures of merit are reported for the single crystal PTS (polydiacetylene poly (bis para-toluene sulfonate) of 2,4-hexadiyne-1,6 diol). Included are the effects of the absorption mechanisms from linear up to four-photon over the wavelength range 1.2-2.2 mum

One-Dimensional Spatial Solitary Waves Due To Cascaded Second-Order Nonlinearities In Planar Waveguides

We report an experimental observation of one-dimensional spatial solitary waves due to cascaded second-order optical nonlinearities

Multisoliton Generation By Laser Modes In A Frequency Doubling Medium

We demonstrate that the number of solitons generated by laser modes with multiple power maxima in a phase-matchable, second-order, nonlinear optical medium can be explained by a model based on field overlap and neighboring soliton interactions

Applications of cascading nonlinear optics to all-optical devices

The application of a cascaded phase shift to a fully integrated nonlinear directional coupler (NLDC) and Mach-Zehnder interferometer (MZI) is presented. It shows that for MZI, the input power was increased and the throughput was modulated between 80% and 20% of the input. For the NLDC, the switching from the cross to the bar states is clear

Modal Dispersion Phase Matching Over 7 Mm Length In Overdamped Polymeric Channel Waveguides

Phase-matched second harmonic generation over 7 mm is demonstrated using the modal dispersion of a composite 4-dimethylamino-4\u27-nitrostilbene/polyetherimde channel waveguide. For a l-mm-long sample a record figure of merit for polymers of eta=P-2 omega/(P(omega)L(2))=14%/W cm(2) was measured at 1550 nm. This is comparable to the value reported for LiNbO3 at that wavelength. The efficiency in longer samples is limited by fundamental and harmonic waveguide-losses

Efficient Wavelength Shifting Over The Erbium Amplifier Bandwidth Via Cascaded Second Order Processes In Lithium Niobate Waveguides

We investigate two schemes for wavelength conversion based on the cascading of two successive second order processes in a quasi-phase-matched lithium niobate channel waveguide. Efficient conversion over the full erbium amplifier bandwidth is possible with a single multi-hundred milliwatt pump laser operating around 1.55 mu m

Optimization of second harmonic generation and nonlinear phase-shifts in the Cerenkov regime

We present beam propagation method (BPM) studies of second harmonic generation (SHG) and nonlinear phaseshifts by cascading. The studies concentrate on SHG by means of radiation modes; the Cerenkov regime. The presented modeling does take into account both depletion and nonlinear phase shifts of the fundamental fields. BPM results show that leaky waves play an important role offering possibilities for enhancing the efficiency of SHG by orders of magnitude over general Cerenkov processes. Using a simple model and taking into account symmetry considerations, we identify the leaky modes that are important for the ¿(2)-processes in the structures that we investigate

Local and external factors affecting the photodegradation of 4N,N \u27-dimethylamino-4 \u27 nitrostilbene polymer films

The photodegradation of the electro-optic chromophore 4N,N\u27-dimethylamino-4\u27nitrostilbene was investigated as a function of wavelength, temperature, local atmosphere, and local molecular environment, i.e., attached as a side chain to a polymer or dissolved as a guest in a host polymer

Effects Of Dispersive 2-Photon Transitions On Femtosecond Pulse-Propagation In Semiconductor Wave-Guides

It is demonstrated that the frequency spectrum of femtosecond pulses becomes highly asymmetric when propagating as transverse magnetic modes in semiconductor multiple quantum well channel waveguides at photon energies near half the band gap. Calculations based on the frequency dispersion in two-photon transitions provide results consistent with the experiment