Two-stage thermoelectrically cooled InGaAs sensors
Andanta has released two-stage thermoelectrically cooled versions of its range of Indium-Gallium-Arsenide (InGaAs) image sensors. Initially this will be implemented for the low resolution standard version FPA320x256-K (900nm to 1.7μm) and the low resolution extended version FPA320x256-K-2.2 (1.2-2.2μm).
The two-stage cooler device further lowers the chip temperature to -50°C during operation. So far, only about -20°C has been practically possible (with thermal loading) by operating the integrated one-stage thermoelectric cooler.
In addition to the cooler extension, the thermal design of the sensor package has been improved, leading to better heat dissipation from the warm side of the cooler at the lower side of the sensor package. This allows an additional chip temperature decrease by another 10°C during sensor operation.
These thermal innovations will be appreciated by all users operating near to the noise threshold of the sensors, as this drops considerably, especially if the sensor dark noise dominates over the sensor readout noise. This is usually the case for applications with low light and longer integration times.
The thermal improvements are especially useful for extended 2.2μm devices, where the dark current is higher compared to the 1.7μm versions.