Study on Bimetal MEMS Calorimeter as Optical Power Standard with High Sensitivity and Large Sensitive Area

Abstract

We investigated the design of a bimetal MEMS calorimeter as a high-sensitivity photo thermal detector. Using finite element method, the thermo-mechanical sensitivity of large-size bimetal sensors of up to 5 mm × 5 mm area, which can be fabricated by the standard MEMS processes, was simulated. Several designs were found to have noise equivalent power (NEP) of one order smaller than that of conventional thermo module type photo thermal sensors with similar size. Experimental results for the first prototype of the MEMS sensors also supported those numerical predictions. This will be expected to provide high throughput absolute spectral optical power measurement.