  We consider string pair production in non homogeneous electric backgrounds.
We study several particular configurations which can be addressed with the
Euclidean world-sheet instanton technique, the analogue of the world-line
instanton for particles. In the first case the string is suspended between two
D-branes in flat space-time, in the second case the string lives in AdS and
terminates on one D-brane (this realizes the holographic Schwinger effect). In
some regions of parameter space the result is well approximated by the known
analytical formulas, either the particle pair production in non-homogeneous
background or the string pair production in homogeneous background. In other
cases we see effects which are intrinsically stringy and related to the
non-homogeneity of the background. The pair production is enhanced already for
particles in time dependent electric field backgrounds. The string nature
enhances this even further. For spacial varying electrical background fields
the string pair production is less suppressed than the rate of particle pair
production. We discuss in some detail how the critical field is affected by the
non-homogeneity, for both time and space dependent electric field backgrouds.
We also comment on what could be an interesting new prediction for the small
field limit. The third case we consider is pair production in holographic
confining backgrounds with homogeneous and non-homogeneous fields.
