Acreo in Sweden has been invovled in Quantum Well IR Photodetector (QWIP) reserach and development since 1986. During the first years a small group led by Jan Andersson was dedicated to research on QWIP structures and means of coupling radiation into the quantum-well structure. One of the resarech results is a 2D optical grating couler to create an optimal elecgtric field pattern for highest possible absorption and responsivity. Acreo holds a patent for this grating coupler. Since 1988 FLIR Systems, later FMV, Saab Dynamics, Celsius Tech and NUTEK have sponsoered an R and D project with the goal to develop QWIP detectors and start up production. Soon it became clear that an adapted ROIC deisng and the hybridization of the focal plane array are key issues in order to achieve the highest possible performance and operability of the complete detector device for voluem production. Extended measures where taken in 1996. In 1997 the industrial interest increased further, ClesiusTech and Saab Dynamics, merged in 2000, and now a division of FLIR Systems AB started to sponsor the R and D project. Because of its success during the last years it has now been expanded and scheduled until 2003 and beyond. Volume production of QWIP FPAs started in 2000.