Micromachined multicavity grey body emitter for the use in MIR spectroscopic systems

A grey body emitter based on a microcavity array with Pt-heater on the backside is presented. The microcavity array is made by electro-chemical etching of silic on. It has been shown in a previous work, that this emitter has especially in th e spectral region >8 µm significantly higher emissivity than commercial availabl e emitters. Due to the thin-film technology of MEMS-based emitters, these types can be typically operated with a maximum temperature of 700°C to 800°C. Higher t emperature causes degradation of the heater. But higher temperatures also mean a n enhancement in radiation power and thus open a wider area of application. The presented work shows a temperature enhanced thermal emitter with a ceramic heate r passivation. Short time tests show the possibility of a maximum temperature of 1000°C. The part of light emitted by the microcavities in comparison to the who le device as well as the influence of the pore size concerning the emitted spect ral range is investigated. The results are the basis for a redesign of the micro cavity array for an enhancement of the geometry tuned emissivity.