Thermal-image sensor designer and manufacturer ULIS reports having achieved unmatched performance with its bolometer (a type of thermal sensor) that now meets speeds of fast imaging applications. It has gained a response time that is four-times greater than standard bolometers. The company says it has achieved this faster speed without any trade-off in sensitivity and is the first to overcome this technological challenge in its aim to significantly raise the overall Factor of Merit (FoM) of bolometers. FoM is a relative measure of thermal sensor sensitivity against response rate. It is a critical parameter camera makers use to compare the performance of thermal sensors.
In contrast to standard bolometers, ULIS’ quicker response time means that it can detect fast moving objects without producing a blurred image. This pixel technology enhancement, in conjunction with the bolometer’s comparably lower price, make it very desirable for inclusion in machine vision cameras, where high frame rates for in-line quality inspection are required but previously the cost of adopting thermal imaging had been prohibitive. The bolometer will also have wider application in defense, such as missile warning systems.
ULIS’ pixel technology achieves an FoM of 125 to 150mK.ms, enabling sharper images that aim to improve the quality of in-line production controls, such as automated glass manufacturing line monitoring. ULIS presented its results in a technical paper entitled: ‘ULIS Bolometer for Fast Imaging Applications Sets New Response Time Record’ at OPTO2018 in Paris. They showed gains in FoM performance from the standard NETD=50mk multiplied by TTC=10 to 12ms (meaning FoM 500 to 600mK.ms) to a new level of NETD=50mK multiplied by TTC=2.5 – 3ms (meaning FoM 125 to 150mK.ms), a four-fold improvement. For more details, checkout the ULIS bolometer page.