A media-defined optical logic circuit composed of a set of light-transmitting polyhedral prisms arranged so that a pair of adjacent prisms can exchange photonic signals through adjacent surfaces. Each prism contains one or more quantum dots that, when excited by a photonic signal received from an adjacent prism, respond by emitting light that becomes an incoming photonic signal for an adjacent prism. Photonic signals are propagated through the circuit in this manner along light-guide paths created by shading certain surfaces to render them fully or partially opaque. The prisms and shading are arranged such that the circuit performs a certain logic function. When the circuit receives a set of photonic input signals representing a binary input value, the circuit responds by emitting a set of photonic output signals that represent a binary output value determined by performing the logic function upon the binary input value.