  Weakly coupled high-Q nanophotonic cavities are building blocks of slow-light
waveguides and other nanophotonic devices. Their functionality critically
depends on tuning as resonance frequencies should stay within the bandwidth of
the device. Unavoidable disorder leads to random frequency shifts which cause
localization of the light in single cavities. We present a new method to finely
tune individual resonances of light in a system of coupled nanocavities. We use
holographic laser-induced heating and address thermal crosstalk between
nanocavities using a response matrix approach. As a main result we observe a
simultaneous anticrossing of 3 nanophotonic resonances, which were initially
split by disorder.
