Related papers: Continuous-wave backward frequency doubling in per…
Periodically poled lithium niobate (PPLN) is a widely used nonlinear optical device for second harmonic generation (SHG). Despite its wide adoption in commercial systems, its bandwidth for SHG is fundamentally limited by the quasi-phase…
In this paper, we proposed and numerically demonstrated a giant enhancement up to 108 in both forward and backward propagation of the Second Harmonic Generation by combining the high-quality factor cavities of the Bound States in the…
Lithium niobate (LN) thin film has recently emerged as an important platform for nonlinear optical investigations for its large $\chi^{(2)}$ nonlinear coefficients and ability of light localization. In this paper, we report the first…
Optical waveguides made from periodically poled materials provide high confinement of light and enable the generation of new wavelengths via quasi-phase-matching, making them a key platform for nonlinear optics and photonics. However, such…
Bringing efficient second-order nonlinear effects in integrated photonics is an important task motivated by the prospect of enabling all possible optical functionalities on chip. Such task has proved particularly challenging in silicon…
The nonlinear (NL) optical response of bulk lithium niobate (LiNbO$_3$) was investigated at 532 nm using the second harmonic of a Nd:YAG laser delivering pulses of 12 ps. The experiments were performed using the D4$\sigma$ method combined…
We report an application of the tri-dimensional pseudo-spectral time domain algorithm, that solves with accuracy the nonlinear Maxwell's equations, to predict second harmonic generation in lithium niobate ridge-type waveguides with high…
We report on bulk and guided-wave second-harmonic generation via random Quasi-Phase-Matching in Lithium Tantalate. By acquiring the far-field profiles at several wavelengths, we extract statistical information on the distribution of the…
Chip-integrated nonlinear photonics holds the key for advanced optical information processing with superior performance and novel functionalities. Here, we present an optimally mode-matched, periodically poled lithium niobate nanowaveguide…
Prospective integrated quantum optical technologies will combine nonlinear optics and components requiring cryogenic operating temperatures. Despite the prevalence of integrated platforms exploiting $\chi^{(2)}$-nonlinearities for quantum…
Nonlinear optical effects have been studied extensively in microresonators as more photonics applications transition to integrated on-chip platforms. Due to low optical losses and small mode volumes, microresonators are demonstrably the…
Periodically poled thin film lithium niobate waveguides provide simultaneous access to efficient second and third order nonlinear processes, enabling broadband generation of coherent laser light. Here, we demonstrate the generation of a…
Second harmonic generation in thin film periodically poled lithium niobate (PPLN) is constrained by an efficiency-bandwidth trade-off and fabrication-sensitive scaling. We demonstrate a racetrack resonator incorporating a short PPLN section…
Quasi-phasematched interactions in waveguides with quadratic nonlinearities enable highly efficient nonlinear frequency conversion. In this article, we demonstrate the first generation of devices that combine the dispersion-engineering…
Nonlinear metasurfaces provide a route to compact frequency conversion by replacing phase matching and long interaction lengths with resonantly enhanced light matter interaction in subwavelength structures. Extending this capability to…
Second harmonic generation (SHG) is a coherent nonlinear phenomenon that plays an important role in laser color conversion. Lithium niobate (LN), which features both a large band gap and outstanding second-order nonlinearities, acts as an…
We observe high optical quality factor (Q) polygonal and star coherent optical modes in a lithium niobate microdisk. In contrast to the previous polygon modes achieved by deformed microcavities at lower mechanical and optical Q, we adopted…
We demonstrate efficient second harmonic generation in a quasi-phase-matched, high quality factor ($Q_0 \approx 5.3\times 10^5$) racetrack microresonator. The observed normalized conversion efficiency is about $3.8\%~mW^{-1}$.
Comparative analysis of second harmonic generation in ordinary and backward-wave settings is presented. Extraordinary properties of frequency doubling nonlinear optical reflectivity and pulse shaping through phase matching of ordinary and…
High complexity, dense integrated nanophotonic circuits possessing strong nonlinearities are desirable for a breadth of applications in classical and quantum optics. In this work, we study natural phase matching via modal engineering in…