Sum frequency generation in pure zinc-blende GaAs nanowires

Nonlinearity of semiconductor nanowires makes them potential frequency converters in nanoscale optoelectronics. Here we demonstrate that sum frequency generation signals can be acquired from GaAs nanowires when excited by a femtosecond laser at 1048 nm and a tunable optical parametric oscillator ranging from 1416 nm to 1770 nm. The SFG intensity is insensitive to the polarization but quite sensitive to the temporal overlap of incident lasers pulses. It is shown that they can work for pulsewidth measurement of femtosecond lasers in the near infrared band. Our results suggest GaAs NWs to be excellent optical nonlinear mixers in nanoscale optoelectronics.