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Uncooled infrared (IR) detectors have a wide range of applications in consumer and industry. They realize the conversion from IR radiation to thermal heat through an absorber. Absorptivity is the main evaluation parameter of this radiation conversion efficiency. Measuring the absorptivity is of great importance in evaluating detectors' performance. In this work, according to Kirchhoff's law of thermal radiation, the absorptivity in a whole IR spectral range is extracted from relation of thermal conductance to absorber temperature only utilizing Joule effect of detectors. The absorptivity in a certain IR spectral range is obtained with the established relationship of absorptivity between different IR spectral ranges. The experiment applying this method is carried out using a thermopile detector integrated with a N-polysilicon heater. And for verification and comparison, the measurement with blackbody optical system and the theoretical calculation are also performed. All results are consistent well with each other, which verifies the validity of the proposed method. This method has the advantage of no sample preparation requirement and is an in-situ self-test measurement. [2021-0185]

Defective pixels always exist in an uncooled infrared focal plane array (IR FPA), and have a significant impact on image quality. To fundamentally reduce defective pixels and improve IR FPA’s reliability, failure analysis (FA) is critically needed. In this work, a self-test (ST) method is proposed to detect the structural failures of uncooled IR FPA. Based on the lumped thermal parameters of a pixel, a structural failures model is presented, and an electrical circuit is designed. The insufficient released, normal released, over released and contaminated IR FPAs are measured. The measured results show that their lumped thermal parameters have a clear differentiation, which not only experimentally verifies the validity of this method, but also shows that it is an effective method for nondestructive analysis of structural failures.

By using networked arrangement, the interconnect complexity of multi-pixel thermopile sensor could be greatly simplified, but there is crosstalk effect among pixels that will cause measurement errors. In this paper, based on the Kirchhoff’s current and voltage laws, a mathematical model of multi-pixel thermopile sensors with networked arrangement is developed. The influence of adjacent pixels’ actual response voltage, resistance and array size on the measurement error of measured pixel is evaluated by simulations. Experiment is carried out using a prototype of $8\times 8$ thermopile array constructed by thermopile detectors. The experimental and simulated results are in good agreement with each other, which verifies the validity of mathematical model. Moreover, this model indicates that the actual response voltage of each pixel in multi-pixel thermopile sensors with networked arrangement cannot be solved without introducing more equations.

Microbolometer is often packaged in a vacuum atmosphere of