The DC current-voltage characteristics induced Ly a driving electric field
with frequency Omega of a one-dimensional electron channel with a tunnel ba
rrier is calculated. Electron-electron interaction of finite range is taken
into account. For intermediate interaction strengths, the non-linear diffe
rential conductance shows cusp-like minima at bias voltages m (h) over bar
Omega/e (m integer) that are a consequence of the finite non-zero range of
the interaction but are independent of the shape of the driving electric fi
eld. However, the frequency-scaling of the photo-induced current shows a cr
oss-over between Omega(-1) and Omega(-2), and depends on the spatial shape
of the driving field and the range of the interaction.