We experimentally demonstrate tunable coupled cavities based upon open access zero-
dimensional hemispherical microcavities. The modes of the photonic molecules are strongly
coupled with quantum well excitons forming a system of tunable polaritonic molecules. The
cavity-cavity coupling strength, which is determined by the degree of modal overlap, is
controlled through the fabricated centre-to-centre distance and tuned in-situ through
manipulation of both the exciton-photon and cavity-cavity detunings by using …