Nonlinear optical processes, which are of paramount importance in science and technology, involve the generation of new frequencies. This requires phase matching to avoid that light generated at different positions interferes destructively. Of the two original approaches to achieve this, one relies on birefringence in optical crystals, and is therefore limited by the dispersion of naturally occ...

The ease of integration and a large second-order nonlinear coefficient of atomically thin layered two-dimensional (2D) materials presents a unique opportunity to realize second-order nonlinearity in a silicon compatible integrated photonic system. However, the phase-matching requirement for second-order nonlinear optical processes makes the nanophotonic design difficult. We show that by nano-pa...

We suggest and discuss two techniques that could radically improve the efficiency of large-scale nonlinear frequency upconversion: quasi-phase matching of high-order harmonic generation in density-modulated media and high-order difference-frequency mixing in plasma. We demonstrate theoretically that both techniques permit optimal phase matching with tight focusing of pump beams, which is detrim...

Abstract The properties of non-collinear phase-matching (PM) for potassium dihydrogen phosphate (KDP) crystal were calculated. calculated numerically type I phase matching and II-phase matching. group delay dispersion (GDD) was determined KDP at different slant angles types 0°, 40°, 60°, 900°. pumping, signal, idler wavelengths 354.7nm, 1064nm, 532nm respectively. time deepened on the angle thr...

Biaxial BaGa4S7 and BaGa4Se7 crystals have been grown by the Bridgman-Stockbarger technique in sufficiently large sizes and with good optical quality to measure the refractive indices and analyze the phase-matching configurations. ©2011 Optical Society of America OCIS codes: (160.4330) Nonlinear optical materials; (190.4410) Nonlinear optics, parametric processes.

We report an analytical description of four wave mixing in lumped optical transmission systems deploying mid-link optical phase conjugator, and provide corroborating simulation results matching theoretical predictions for four wave mixing and for modulated signals. OCIS codes: (190.4380) Nonlinear optics, four-wave mixing; (060.4510) Optical communications.

This paper presents a robust phase correlation technique and a compound phase correlation method for reliable sub-pixel image feature matching and motion estimation. A phase fringe filter and a highly robust estimator QMDPE are used to improve the fitting accuracy of the phase difference plane in Fourier domain. A compound phase correlation method is proposed to identify and decompose the multi...

We review recent experimental and theoretical work on the use of counterpropagating light to enhance high-order harmonic generation through all-optical quasi-phase matching. Also presented is a new technique for measuring the coherence of high harmonics in the nonlinear medium. This information is crucial for understanding the process of harmonic generation over extended distances, as well as f...

a r t i c l e i n f o We present detailed description of so-called phase-reversed structures that are characterized by two grating wave vectors allowing simultaneously phase-match two parametric three-wave processes. The novelty is that the structure is realized as a definite assembly of nonlinear segments leading to detailed description of cascaded three-photon processes with the parameters of...

We propose a simple means for compressing optical pulses with second-harmonic generation. Aperiodic quasi-phase-matching gratings impart a frequency-dependent phase shift on the second-harmonic pulse relative to the fundamental pulse and can be engineered to correct for arbitrary phase distortions. The mechanism is discussed, and a detailed analysis of the compression of quadratic phase (linear...