Laser irradiation of a solid surface under an oxidizing ambient gas can activate localized, heterogeneous chemical reactions which modify the surface. Under suitable conditions, the laser initiates a reactive plasma near the gas/solid interface. This plasma mechanism is proposed as the basis for a new surface chemical technique which we denote laser-pulsed plasma chemistry (LPPC). LPPC experiments on niobium metal under one atmosphere of oxygen employed a pulsed CO2 laser and displayed single-pulse, self-limiting, oxide growth. Product oxide thickness increased with optical intensity. Surface layer thickness and chemical composition were determined for oxide layers between 1 nm and 5 nm thick using x-ray photoelectron spectroscopy (XPS or ESCA). Composition of these niobium oxide (Nb2O5−δ) surfaces was similar to the composition produced by RF plasma oxidation, but the valence defect, δ, for LPPC oxides was approximately two to five times lower. At high laser intensity (≥4 × 106 W/cm2), direct optical heating or plasma-mediated thermal coupling to the solid activates interdiffusion at the oxide/metal interface.