The surface temperature inside an optical engine was measured both with and without heating the intake gas. The temperature distribution was measured by lifetime-based phosphor thermometry using 10 time-sequential images during a single decay recorded by a non-intensified high-speed complementary metal oxide semiconductor camera and by accounting for the pixel-to-pixel variation in the nonlinearity of the sensor. Consequently, the system was simple and compact. One goal of this research is to use a single camera to measure the temperature field because it is easy to use such a system in practical experiments. The shot-to-shot standard deviation of the decay constant for uniform temperature conditions was 0.17-0.33% at 80-160 degrees C and it varied +/- 0.15% with position, indicating that the pixel nonlinearity is highly nonuniform. The present measurement method had a measurement error of -2.25 to 1.15 degrees C and it exhibited a similar level of shot-to-shot fluctuations (+/- 0.42-2.34 degrees C). This technique was used to measure the temperature in an optical engine and it gave reasonable temperature maps. (C) 2011 Elsevier Ltd. All rights reserved.