Photon trapping and transfer with solitons

We show, numerically, that a single photon trapped by a soliton in a Kerr nonlinear medium can be transferred from one soliton to another when the captor soliton undergoes collision with a second soliton. Soliton collisions can also be used in this way to realize a beam splitter, as well as a mode-separating beam splitter, analogous to the usual polarizing beam splitter. We discuss briefly the feasibility of an optical fiber implementation and possible applications to quantum-information processing.

Figure 1

(Color online) An example of photon transfer. Top: The pump solitons. The soliton parameters in the notation of [11] are $k_1=1.5$, $k_2=-1.5+0.5i$, ${\mu }_p=0.1$ (${\gamma }_p=0.02$, ${\beta }_{2p}=-0.2$), and the amplitudes of both (scalar) solitons are 4. The relative phase at collision is arranged to be $\pi$. Bottom: The probe when launched in the state ∣11⟩. The parameters for the probe propagation are ${\gamma }_s=0.01333$ and ${\beta }_{2s}=-0.1333$ $(\ell =1)$. The photon is transferred to the overtaking soliton.

Figure 2

(Color online) The probe when launched in the state ∣21⟩. In this case ${\gamma }_s=4$ and $k_2=-1.5+0.8i$, so that the soliton collision takes place at a greater relative velocity. The system acts as an ordinary nonpolarizing beam splitter.

Figure 3

(Color online) Top: The probe when launched in the excited state ∣21⟩, with the same parameters as for Fig. 2, except ${\gamma }_s=8$. The photon in this case stays in large part with its original captor soliton. Center: The probe when launched in the state ∣22⟩. The photon is transferred to the faster soliton, as in the ∣11⟩ case shown in Fig. 1. Bottom: The probe when an equal linear combination of ground and excited states, $\mid 22⟩+\mid 21⟩$, is launched. The system is analogous to a polarizing beam splitter.

Figure 4

(Color online) Probe waveform profiles for the linear combination case shown in Fig. 3 (bottom).