Search results for "Linear optics"

MAPPATURA DEL DISORDINE NON LINEARE MEDIANTE INTERAZIONE PARAMETRICA A TRE ONDE

2010

We introduce a simple approach for characterizing the ferroelectric domain distribution in bulk quadratic crystals. The approach is demonstrated in a lithium tantalate sample with periodic electric field poling and random mark-to-space ratio.

Nonlinear Disorder Mapping Via Three-Wave Mixing in Quadratic Crystals

2010

Guided-wave frequency doubling in surface periodically poled lithium niobate: competing effects

2007

We carried out second-harmonic generation in quasi-phase-matched ? -phase lithium niobate channel waveguides realized by proton exchange and surface periodic poling. Owing to a limited ferroelectric domain depth, we could observe the interplay between second-harmonic generation and self-phase modulation due to cascading and cubic effects, resulting in a nonlinear resonance shift. Data reduction allowed us to evaluate both the quadratic nonlinearity in the near infrared as well as the depth of the uninverted domains. © 2007 Optical

Continuous-Wave Backward Frequency Doubling in Periodically Poled Lithium Niobate

2010

We report on backward second-harmonic- generation in periodically poled lithium niobate with a 3.2 micron QPM period. A tunable continuous-wave Ti:Sapphire laser allowed us exciting two resonant orders. Experimental data compared well with standard theory.

Wavelength tuning of femtosecond pulses generated in nonlinear crystals by using diffractive lenses

2010

We demonstrate that diffractive lenses (DLs) can be used as a simple method to tune the central wavelength of femtosecond pulses generated from second-order nonlinear optical processes in birefringent crystals. The wavelength tunability is achieved by changing the relative distance between the nonlinear crystal and the DL, which acts in a focusing configuration. Besides the many practical applications of the so-generated pulses, the proposed method might be extended to other wavelength ranges by demonstrated similar effects on other nonlinear processes, such as high-order harmonic generation.

Nonlinear higher-order polariton topological insulator

2020

We address the resonant response and bistability of the exciton-polariton corner states in a higher-order nonlinear topological insulator realized with kagome arrangement of microcavity pillars. Such states are resonantly excited and exist due to the balance between pump and losses, on the one hand, and between nonlinearity and dispersion in inhomogeneous potential landscape, on the other hand, for pump energy around eigen-energies of corresponding linear localized modes. Localization of the nonlinear corner states in a higher-order topological insulator can be efficiently controlled by tuning pump energy. We link the mechanism of corner state formation with symmetry of the truncated kagome…

Determination of third-order nonlinear optical properties of ABI derivatives

2019

This material is based upon work supported by the ERDF 1.1.1.1 activity project Nr. 1.1.1.1/16/A/046 “Application assessment of novel organic materials by prototyping of photonic devices”.

Supercontinuum optimization for dual-soliton based light sources using genetic algorithms in a grid platform

2014

We present a numerical strategy to design fiber based dual pulse light sources exhibiting two predefined spectral peaks in the anomalous group velocity dispersion regime. The frequency conversion is based on the soliton fission and soliton self-frequency shift occurring during super- continuum generation. The optimization process is carried out by a genetic algorithm that provides the optimum input pulse parameters: wavelength, temporal width and peak power. This algorithm is implemented in a Grid platform in order to take advantage of distributed computing. These results are useful for optical coherence tomography applications where bell-shaped pulses located in the second near-infrared wi…

Scaling guidelines of a soliton-based power limiter for 2R-optical regeneration applications

2010

International audience; In this work, we report scaling rules for the design of an all-fibered soliton-based power limiter for reamplification and reshaping (2R) regeneration process. In particular, we propose general guidelines to fix the optimum fiber length and initial power of the regenerator. We quantitatively point out the optical power limiting effect of the device enabling a significant reduction of the amplitude jitter of a degraded signal. Influence of the initial level of amplitude jitter is discussed and the results are compared with a self-phase modulation-based configuration working in the normal dispersion regime. Realistic numerical simulations in the context of 160 Gbit/s s…

Design of All-Normal Dispersion Microstructured Optical Fiber on Silica Platform for Generation of Pulse-Preserving Supercontinuum Under Excitation a…

2017

We investigated numerically the possibility of all normal dispersion fiber design for near-infrared supercontinuum generation based on a standard air-silica microstructure. The design procedure includes finding of target dispersion profile and subsequent finding of appropriate geometrical fiber design by inverse dispersion engineering. It was shown that the tailoring of dispersion profile could increase the spectral width of generated supercontinuum while maintaining perfect spectral flatness. Conditions necessary for wide and flat supercontinuum generation as well as restrictions imposed by chosen materials were discussed. As a result of design and optimization procedure, an air-silica des…