  The interaction of waves in nonlinear Kerr waveguides are, under some
circumstances, similar to the physics occurring at the horizon of black and
white holes. Here, we investigate this analogy in an integrated nonlinear
photonic structure through the reflection of a continuous wave on an intense
pulse. The resulting frequency conversion of the continuous wave is
experimentally demonstrated in a silicon photonic wire waveguide and confirmed
by simulations using the generalized nonlinear Schr\"odinger equation. This
demonstration paves the way to efficient all-optical signal processing
functionality integrated on a CMOS-compatible waveguide platform.
