Efficient thermal infrared emitter with high radiant power

Abstract. Sensitive and selective gas measurements are crucial for a large variety of applications, e.g., explosion protection. Optical gas detection is usually based on the gas' absorption of infrared radiation (IR). It is the leading technique in terms of accuracy, reliability, and economic efficiency. Since most gas measurements are made in the two wavelength ranges of (3 ... 5) and (8 ... 14) μm, a broadband IR source is necessary. In this paper, we report on a novel thermal IR emitter with high radiant power and a near-blackbody emission characteristic that can be modulated electrically. The layout of the IR source had been optimized by use of finite element analyses (FEA) in order to get an adequate electrical resistance as well as a homogeneous temperature distribution and a minimum deflection of the radiating element. Due to its excellent thermal isolation from the heat sink, the electrical power consumption is very low. Operating temperatures of up to 1400 K are possible, so that the fabricated IR source features a very high radiant power. Its application in gas analysis will improve the performance and efficiency of gas measurement systems.