Here the promotion of flame acceleration and deflagration-to-detonation transition (DDT) using the distributed photo ignition of photo-sensitive nanomaterials suspended in fuel/oxidizer mixtures is demonstrated for the first time. Distributed photo ignition was carried out by suspending single-walled carbon nanotubes (SWCNTs) with Fe impurity in quiescent C2H4/O-2/N-2 mixtures and flashing them with an ordinary Xe camera flash. Following the flash, the distributed SWCNTs photo ignite and subsequently provide a quasi-distributed ignition of the C2H4/O-2/N-2 mixture. In a closed detonation tube the quasi-distributed photo ignition at one end of the tube leads to the promotion of flame acceleration and DDT and, for sensitive C2H4/O-2 mixtures, appears to lead to direct detonation initiation or multiple combustion fronts. The DDT run-up distance, the distance required for the transition to detonation, was measured using ionization sensors and was found to be approximately a factor of 1.5x to 2x shorter for the distributed photo ignition process than for traditional single-point spark ignition. It is hypothesized that the increased volumetric energy release rate resulting from distributed photo-ignition enhances DDT due to the decreased ignition delay and greater early-time flame area and turbulence levels, which in turn result in accelerated formation and amplification of the leading shock and accelerated DDT. (C) 2011 The Combustion Institute. Published by Elsevier Inc. All rights reserved.