A Time-Efficient Self-Test Method for Evaluating Thermal Parameters of Uncooled Infrared Detectors

Uncooled infrared (IR) detectors are widely used in industry and civil imaging fields. Moreover, thermal parameters have a strong impact on detectors' performance, especially under the trend toward higher spatial resolution. Therefore, evaluating them is important for detectors improvement. In this work, inspired by the traditional optical frequency-domain concept, a self-test method for evaluating thermal parameters of an uncooled IR focal plane array (FPA) is proposed. Utilizing a frequency-adjustable pulsed Joule heating power stimulus, the relationship between the Joule heating power, pixels' thermal parameters, and pixels' response voltage was first analyzed and established. This method was validated experimentally using a 3 x 3 format diode-based detector. For comparison, an experiment applying the steady-state method was also conducted. The results of all experiments were in good mutual agreement, demonstrating the reliability of the proposed method. For a 1280 x 1024 format FPA, the steady-state method needs approximately 90 h to finish measurements, while the proposed method requires only 5 min, illustrating that the proposed self- test method could considerably reduce the thermal parameter testing time for large-scale uncooled IR FPA.