A Simple Fabry-Perot-Based Germanium Bolometer for CO2 Monitoring: Simulation and Measurement

AbstractWe report on the design of a simple germanium bolometer designed as a Fabry-Perot absorbing structure, which can be used for monitoring, e.g., CO2, where no additional filter is required. CO2 is absorbs IR radiation in a major band centered around 4.26μm. The selectivity of the whole sensor-configuration is mainly accomplished by the wavelength-response associated with the Fabry-Perot structure involved. The analysis shows, that the designed bolometer has an adequate response-function for the measurement of CO2 concentration. Combining this analysis for the bolometer with ray tracing simulations for a connected sample chamber yields the response for an entire IR-absorption sensor system, which is in good agreement with measurements