Fast growth of diamond thin films and crystals in open air was achieved by combustion synthesis with resonant laser energy coupling. A pre-mixed C 2H4/C2H2/O2 gas was used as precursors for chemical vapor deposition of diamond. Through the resonant excitation of the CH2 wagging mode of the ethylene (C 2H4) molecules using a CO2 laser tuned at 10.532 μm, high-quality diamond thin films and crystals were grown on various substrates with a high growth rate. The effects of the resonant laser energy coupling were investigated using optical emission spectroscopy and mass spectroscopy. Excitations of precursor molecules by different laser powers were studied. The density of the incident laser power was adjusted to modify diamond crystal orientation, optimize diamond quality, and achieve high-efficiency laser energy coupling. The wavelength-tunable CO2 laser steers the chemical reactions and promotes proportion of intermediate oxide species, which results in preferential growth of (100)-oriented diamond. The wavelengthtunable CO2 laser was also used to resonantly excite the vibration modes of ammonia molecules to synthesize N-doped diamond. The laser wavelength was tuned to match frequencies of the NH wagging mode of the ammonia molecules. Vibrational excitation of the ammonia molecules promotes nitrogen concentration in the deposited diamond films. This study opens up a new avenue for controlled chemical vapor deposition of crystals through resonant vibrational excitations to steer surface chemistry.