Ultrafast mid-infrared interferometric photocurrents in graphene-based two-terminal devices

We demonstrate that graphene-based two-terminal devices allow autocorrelating femtosecond mid-infrared pulses with a pulse duration of about 100 fs in the wavelength regime of 5.5-14 μm. The results suggest that the underlying ultrafast detection principle relies on an electric field dominated autocorrelation in combination with the optoelectronic dynamics at the metal-graphene interfaces. The demonstrated scheme excels because of the ease in nanofabrication of two-terminal graphene-based optoelectronic devices and their robustness.