STM (scanning tunneling microscope) light emission from an evaporated Au fi
lm irradiated by pico second laser pulses has been investigated for various
bias voltages of the STM. The observed emission consists of two components
. The first component that has the same duration as the incident laser puls
e is excited by laser induced tunneling electrons. The second component tha
t has a longer duration than that of the laser pulse is emitted from surfac
e polariton plasmons excited nonlinearly by the laser pulse. (C) 2001 Elsev
ier Science B.V. All rights reserved.