  The engineering of localised modes in photonic structures is one of the main
targets of modern photonics. An efficient strategy to design these modes is to
use the interplay of constructive and destructive interference in periodic
photonic lattices. This mechanism is at the origin of defect modes in photonic
bandgaps, bound states in the continuum and compact localised states in flat
bands. Here we show that in lattices of lossy resonators, the addition of
external optical drives with controlled phase enlarges the possibilities of
manipulating interference effects and allows designing novel types of localised
modes. Using a honeycomb lattice of coupled micropillars resonantly driven with
several laser spots at energies within its photonic bands we demonstrate the
localisation of light in at-will geometries down to a single site. These
localised modes can be seen as fully reconfigurable optical cavities with the
potentiality of enhancing nonlinear effects and of controlling light-matter
interactions with single site resolution.
