Observation of Temporal Vector Soliton Propagation and Collision in Birefringent Fiber

We report the experimental observation of temporal vector soliton propagation and collision in a linearly birefringent optical fiber. To the best of the authors’ knowledge, this is both the first demonstration of temporal vector solitons with two mutually incoherent component fields, and of vector soliton collisions in a Kerr nonlinear medium. Collisions are characterized by an intensity redistribution between the two components, and the experimental results agree with numerical predictions of the coupled nonlinear Schrödinger equation.

Figure 1

Experimental setup.

Figure 2

Arbitrary-amplitude vector soliton propagation. (a) Wavelength shift vs angle to fast axis $\varphi$, numerical curves given by dashed lines; (b) and (d) experimental results for $\varphi =45°$ and 37° with EDFL2, respectively. Inset: input spectrum for EDFL1; (c) and (e) corresponding numerical simulations of $\varphi =45°$ and 37°, respectively.

Figure 3

Demonstration of the phase dependence of energy-exchanging collisions. In (a)–(c) the collision phase $\Delta {\theta }_2$ was determined by the short length of HB-PMF; and (e)–(f) by the long length; (a),(d) experimental result, without collision; (b),(e) experimental result, with collision; (c),(f) simulated collision result with (c) $\Delta {\theta }_2=90°$ and (f) $\Delta {\theta }_2=50°$. Values of the slow-fast power ratio are given above each soliton.

Figure 4

Additional energy-exchanging collisions. In (a)–(c) the collision phase $\Delta {\theta }_2$ was determined by the short length of HB-PMF; and (e)–(f) by the long length; (a),(d) Experiment, without collision; (b),(e) experiment, with collision; (c),(f) simulated collision result, using $\Delta {\theta }_2=90°$ inferred from the experiment of Fig. 3.