Tunable and plasmon-enhanced four-wave mixing on an aluminum grating

Abstract

We report on wavelength-tunable and plasmon-enhanced four-wave mixing (4WM) on an Al grating. When surface plasmons (SPs) are excited at the first and second pump wavelengths, the electromagnetic fields near the grating surface are dramatically enhanced and the corresponding 4WM signals are enhanced by factors of 177 and 42 compared with off resonant conditions. The maximum output power of the 4WM signal is as high as 25 nW. Moreover, by fixing the first pump beam to the SP excitation angle and tuning the second pump beam from 1200 to 1550 nm, we obtain a tunable and enhanced 4WM output from 539 to 600 nm. This setup can potentially be applied to frequency conversion, beam steering and dispersion control.