Using N₂O as an alternative background gas to O₂ when growing oxide thin films by pulsed laser deposition (PLD) was previously expected to result in larger oxygen contents of as-grown thin films. In this work, we investigate the composition and kinetic energy of the pulsed laser induced plasmas that propagated in N₂O and O₂ by using mass spectrometry and plasma imaging. Two distinguished features were observed when using N₂O instead of O₂. (1) In N₂O background gas as compared to O₂, a larger proportion of negative oxygen ions was detected. (2) The alkaline-earth elements were fully oxidized in the N₂O background, which is not achievable in O₂. These observations are attributed to the smaller dissociation energy of the N₂O molecules as compared to O₂. The smaller dissociation energy of the background gas molecule is expected to reduce the interaction strength during their central collisions with the plasma species. As a result, the dissociable or electron detachable plasma species can be formed in larger amounts in N₂O background, compared to O₂. Comparing the composition of the deposited thin films indicates a larger oxygen content of the film grown in N₂O background gas, as compared to O₂, at pressures of ∼10⁻¹ mbar, which is the most commonly used deposition pressure in PLD. Nevertheless, this was not achieved when performing PLD at ∼10⁻² mbar, since the pressure was not high enough to trigger the formation of the shockwave front during the plasma expansion and thereby the lightest oxygen plasma species were preferentially scattered.