Effect of ambient on the thermal parameters of a micromachined bolometer

TL;DR

This paper investigates how ambient environment affects the thermal parameters of micromachined bolometers, revealing that ambient gases alter thermal response characteristics and impact device responsivity.

Contribution

It introduces a model explaining the influence of ambient gases on bolometer thermal response, highlighting the transition from single to multiple time constants.

Findings

Thermal response in vacuum is characterized by a single time constant.

Presence of ambient gas introduces additional thermal mass and diffusion effects.

Implications for frequency-dependent responsivity in bolometer design.

Abstract

The thermal characterization of bolometers is needed for optimal design as well as applications. In this letter, we present results of the effect of environment on the thermal properties of micromachined bolometers. We find that while in vacuum, the thermal response can be represented by a single time constant, in presence of an ambient gas, the thermal response can no longer be described by a single time constant. This will have a direct implication on frequency dependence of responsivity. We present a model to explain our data which involves the finite diffusion time in the ambient gas and the associated extra thermal mass.