Methodological enhancement of NETD optimization through active FPA temperature control

The characterization of figures of merit (FOM) plays a crucial role in numerous applications such as industry, defense, and R&D. Defining parameters for the long-wave infrared (LWIR) focal plane array (FPA) systems is essential for determining the camera’s FOM, particularly the noise equivalent temperature difference (NETD), which evaluates the thermal detection accuracy of a given scene. In previous work, we proposed a novel methodology for reducing the NETD in LWIR imaging, based on a long-time acquisition cycle. However, in that study, the FPA temperature was not controlled, was only monitored, and could vary during acquisition, potentially leading to performance degradation. Now, we expand this methodology by incorporating the FPA temperature control as an operational parameter that can be used in the optimization process. This expanded approach was applied to a commercial FPA with 17 μm pitch amorphous silicon microbolometer pixels. During the procedure, sensor responses were assessed for blackbody temperatures (TBB) ranging from 15 ◦C to 76 ◦C, while varying the integration time (τ ), the compensation bolometer gate voltage (VGSK), and the active bolometer gate voltage (VGFID). The results demonstrate that the FPA temperature control maintains the temperature within ±0.5 ◦C of the desired set point, ensuring greater stability during the characterization process. These findings were also confirmed through an exhaustive search in the parameter space, validating the effectiveness of the expanded methodology.