Six‐wave mixing induced by free‐carrier plasma in silicon nanowire waveguides

Abstract

Nonlinear wave-mixing in mesoscopic silicon structures is a fundamental nonlinear process with broad impact and applications. Silicon nanowire waveguides, in particular, have large third-order Kerr nonlinearity, enabling salient and abundant four-wave mixing dynamics and functionalities. Besides Kerr effect, in silicon waveguide two-photon absorption generates high free-carrier densities, with corresponding fifth-order nonlinearity in the forms of free-carrier dispersion and free-carrier absorption. However, whether these fifth-order free carrier nonlinear effects can lead to six-wave mixing dynamics still remains an open question until now. Here, we report the first demonstration of free-carrier induced six-wave mixing in silicon nanowires. Unique features including inverse detuning dependence of sixwave mixing efficiency, and its higher sensitivity to pump power, are originally observed and verified by analytical prediction and numerical modeling. Additionally, asymmetric sideband generation is observed for different laser detunings, resulting from the phase-sensitive interactions between free-carrier six-wave mixing and Kerr four-wave mixing dynamics. These discoveries provide a new path for nonlinear multi-wave interactions in nanoscale platforms.

Real-time dynamics and cross-correlation gating spectroscopy of free-carrier Drude slow-light solitons

“…In both regions, the spectra drop off as the increase of frequency detuning due to the 1/ term in Eq. 10 [45]. Moreover, it is seen from Eq.…”

Six-wave interaction with double wavefront reversal in multimode waveguides with Kerr and thermal nonlinearities

“…Six-wave interaction with double wavefront reversal in multimode waveguides with Kerr and thermal nonlinearities. Computer Optics 2023; 47 (5): 702-709. DOI: 10.18287/2412-6179-CO-1313.…”

“…С учетом заданных выше приближений в среде с керровской нелинейностью система уравнений, описывающая распространение волн накачки, сигнальной волны, генерацию волны с УОВФ, имеет вид [2,14]: 5) -нелинейная восприимчивость пятого порядка, k 1,2 =  1,2 /c, n (x,  1,2 ) -значение показателя преломления на частоте  1,2 , x -поперечная координата. Пусть модами волновода являются функции: )exp .…”

“…При переходе от рассмотрения шестиволнового взаимодействия в неограниченных по поперечным размерам нелинейных средах к волноводам [5] появляется возможность, как и в случае четырехволновых взаимодействий [6 -10], за счет увеличения длины взаимодействия без существенного изменения на этой длине интенсивности взаимодействующих волн значительно повысить эффективность преобразования излучения.…”

On‐Chip Electrically Driven Tunable Meta‐Lens for Dynamic Focusing and Beam Steering

“…Many tunable mechanisms have been widely exploited for dynamic control of guiding waves in PICs. Different types of tunable, reconfigurable, and programmable devices have been extensively reported based on electro-optic (EO) effect, [24][25][26] free carrier effect, [27] thermo-optic (TO) effect, [28][29][30] and crystal phase change effect. [31][32][33] Several related devices and functions have been proposed and demonstrated, such as on-chip reconfigurable wavefront shaping, [24,25] thermally tunable varifocal metalens, [29] scalable silicon 1 × N switch, [30] focusing and defocusing switching.…”