Directional light emission of NO in the far infrared region has been analyzed. Two main stimulated emission channels around 27 mu m (approximate to 11 THz) and 14 mu m for the 8s sigma(2)Sigma(+)(V = 0) level have been identified as the 8s sigma -> 7p sigma and 8s sigma -> 6f transitions, respectively. Two dominant band systems around 19 and 21 pin for the 815(v = 0) complex have been assigned to the 8f -> 7g and 8f -> 7d sigma transitions, respectively. The possibility of the black body induced transitions is briefly discussed. (c) 2007 Elsevier B.V. All rights reserved.