Linear optics
= Linear optics
In <linear optics>, the response is linear in the optical field and propagation or passive mixing maps mode <annihilation operators> to linear combinations of mode <annihilation operators>. <Wave plates> and beam splitters can rotate or mix photonic modes, but do not by themselves supply a deterministic interaction between independent photon-number <qubits>. Conditional measurements and auxiliary <photons> change that resource model.