LED-spectroscopy based on multi quantum well emitter

This paper provides information about LED-based spectroscopy, in particular regarding to the use of multi quantum well LEDs and its special characteristics. The advantages of LED-based spectroscopy for sensor application have already been published. We could demonstrate the feasibility of high resolution, real time in-situ measurements also in harsh environment using the LED-spectroscopy with standard light emitting diodes. In previous work we where presenting the principles and results of LED-spectroscopy using standard LEDs. This method is suitable almost for substances with broadband absorption characteristics. This paper presents the significant advantages of using modern multi quantum well (MQW) light emitters in spectroscopic application. This enables the measurement of substances with narrow band absorption characteristics such as benzene, toluene, formaldehyde, ammonia or nitrogen monoxide. Thus it enlarges the field of applications by a huge number of chemical components. Example measurement of nitrogen monoxide is provided.