Pulsed laser deposition (PLD) in conjunction with a synchronized pulsed gas source provides an extra degree of freedom in processing the ablation plume. This technique is called pulsed reactive crossed-beam laser ablation (PRCLA). The ablation plasma of La0.6Ca0.4CoO3 (LCCO) produced by KrF excimer laser (248 nm) irradiation is analyzed by spatially and temporal resolved optical emission spectroscopy in the range of 300-800 nm in vacuum, with oxygen background and with an additional N2O as a gas pulse. The spectra reveal higher intensities for all the peaks when the gas pulse is applied. No new peaks assigned to the interaction with the gas pulse, i.e. oxygen, nitrogen or diatomic species are observed. The maximum intensities of the plasma with the gas pulse are observed later in time and further away from the target. (C) 2002 Else vier Science B.V. All rights reserved.