All-optical transistor using an optical event horizon

We show by experiment that scattering of an optical pulse at an optical event horizon provides an unprecedented potential for controlling the properties of a light pulse with another light pulse. Most importantly, with proper parameter selection, a strong pulse can be switched by a 7 times less energetic pulse, which clearly sets our method apart from almost any other previously proposed optical transistor. Moreover, while a gate pulse may experience serious reshaping effects in the normal dispersion regime, a suitably chosen soliton does not dispersively spread or break up into multiple pulses, such that the solitonic switching scheme is cascadable.