Dissipative Polarization Domain Walls in a Passive Coherently Driven Kerr Resonator

Using a passive, coherently driven nonlinear optical fiber ring resonator, we report the experimental realization of dissipative polarization domain walls. The domain walls arise through a symmetry breaking bifurcation and consist of temporally localized structures where the amplitudes of the two polarization modes of the resonator interchange, segregating domains of orthogonal polarization states. We show that dissipative polarization domain walls can persist in the resonator without changing shape. We also demonstrate on-demand excitation, as well as pinning of domain walls at specific positions for arbitrary long times. Our results could prove useful for the analog simulation of ubiquitous domain-wall related phenomena, and pave the way to an all-optical buffer adapted to the transmission of topological bits.

Figure 1

Numerical illustration of the polarization SSB and associated PDWs of Eqs. (1) for $\mathrm{\Delta }=3$ and $B=2$. (a) Stationary cw intracavity intensities versus driving power $X$. Yellow curve: symmetric solutions ($E_1=E_2$; dotted lines are unstable states); blue and orange curves: asymmetric solutions ($E_1\ne E_2$). (b) Temporal intensity profile of a single PDW connecting the two cw symmetry-broken solutions existing for $X=5$. Blue and orange curves correspond to the two polarization modes, while the black curve shows the total power.

Figure 2

Experimental setup. The passive fiber ring resonator is highlighted with an orange background. PG1 and PG2, pattern generators; SW, electrical switch; EDFA, erbium-doped fiber amplifier; PC, polarization controller; PBS, polarizing beam splitter.

Figure 3

Experimental evidence of dissipative PDWs for $X\simeq 30.5$ and $\mathrm{\Delta }\simeq 13.5$. (a)–(c) Round-trip by round-trip evolution of the fast-time output power profile for the two polarization components, $|E_{1,2}(\tau ){|}^2$ [(a), blue, and (b), orange] as well as for the total signal [(c), gray] before and after a short, localized, 400 ps-long polarization perturbation is applied at about round-trip No. 1000. The perturbation generates a blue-mode-dominated domain connected to the surrounding regions by two PDWs. The PDWs drift towards each other, eventually mutually annihilating. (d) Corresponding line plots using matching colors for selected round-trips [marked with dashed side-lines in (a)–(c)]. (e) Evolution of the temporal separation $\mathrm{\Delta }\tau$ between the PDWs.

Figure 4

(a) Demonstration of drifting PDWs being pinned and unpinned to a shallow modulation of the driving polarization. We only show the evolution of the output power of one polarization component. The 10 GHz sinusoidal modulation [transparent shades of red and panel (b)] is applied between round-trips No. 1200 and 2500. (c) Long term pinning of PDWs, for $X\simeq 24$ and $\mathrm{\Delta }\simeq 9.2$. (d) Sampling scope measurement (blue dots) of the temporal intensity profile of the two PDWs trapped in (c). The green curve is the numerical expectation.