Ultra-low-power hybrid light–matter solitons

Abstract

New functionalities in nonlinear optics will require systems with giant optical nonlinearity as well as compatibility with photonic circuit fabrication techniques. Here we introduce a platform based on strong light–matter coupling between waveguide photons and quantum-well excitons. On a sub-millimetre length scale we generate picosecond bright temporal solitons at a pulse energy of only 0.5 pJ. From this we deduce a nonlinear refractive index three orders of magnitude larger than in any other ultrafast system. We study both temporal and spatio-temporal nonlinear effects and observe dark–bright spatio-temporal polariton solitons. Theoretical modelling of soliton formation in the strongly coupled system confirms the experimental observations. These results show the promise of our system as a high speed, low power, integrated platform for physics and devices based on strong interactions between photons.

Modulational instability and solitary waves in polariton topological insulators

“…Main advantages of polaritons include sufficiently strong spin-orbit coupling originating in the cavity induced TE-TM splitting of the polariton energy levels [19,20], established technology of the microcavity structuring into arbitrary lattice potentials [19,21], and very strong nonlinear interactions of polaritons through their excitonic component. The latter was used for recent demonstrations of superfluidity [22,23], generation of dark quasi-solitons and vortices [24][25][26][27], bright spatial and temporal solitons [28][29][30], and other effects. The observed polariton effects with linear and nonlinear lattice potentials include one- [31] and twodimensional [32,33] gap polariton solitons, visualization of Dirac cones [34] and flat bands [35], and visualization of non-topological edge states [21].…”

Temporal dark polariton solitons

“…This system features upper and lower polariton branches having respectively anomalous and normal group velocity dispersions. The latter case in combination with the defocusing excitonic nonlinearity gives rise to bright temporal solitons that have been demonstrated experimentally in [2], while the former case suggests the existence of dark temporal solitons that are under investigation in this Letter.One should mention the link between temporal excitations studied in this Letter and spatial dark polariton solitons forming in planar microresonators upon interaction with an obstacle [8,9]. As these solitons propagate with some slow velocities of few percent of the light velocity, they also can be considered as spatio-temporal structures, but in the case when dispersion of the light mode is shaped by the waveguide cut-off equivalent to the cavity resonance.…”

“…The effective nonlinear parameter  [6] in these waveguides can reach . Thus, such waveguides represent an excellent experimental platform for the demonstration of ultra-low-power self-sustained excitations.Optical modes of a waveguide with single or multiple quantum wells can couple to an excitonic resonance [2][3][4]. In the presence of waveguide spatial localization is mediated by the total internal reflection, i.e.…”

“…Recently planar waveguides and photonic wires operating in the regime of strong coupling between photons and quantum-well excitons have been demonstrated [2][3][4][5] and used for observation of temporal and spatio-temporal solitons. The effective nonlinear parameter  [6] in these waveguides can reach [7].…”

Two-dimensional lattice solitons in polariton condensates with spin-orbit coupling

“…Among main advantages of such systems are well established technologies of the microcavity structuring allowing creation of nearly arbitrary potentials [5][6][7][8][9] and very strong nonlinear interactions of polaritons via their excitonic component. Nonlinear phenomena observed in the exciton-polariton condensates include superfluid behavior upon interaction with cavity defects [4], formation of oblique dark solitons and vortices [10][11][12][13], excitation of bright spatial and temporal solitons [14][15][16][17][18][19][20][21], etc. Periodic potentials created in microcavities support gap solitons in both one- [17,18] and two-dimensional [19,20] settings.…”