In this paper we report on research activities at the Fraunhofer Institute for Solar Energy Systems (ISE) and Concentrix Solar in the area of secondary optics for FLATCON^® modules. This concentrator photovoltaic (CPV) technology is based on Fresnel-lenses as primary optics, passive heat spreaders and triple-junction III-V solar cells. In the first part of the paper, a field performance analysis is presented for Concentrix CPV-systems recently installed in Spain. Subsequently, the performance of the first FLATCON^® modules with reflective and refractive secondaries are evaluated (FLATCON^® II) in indoor and outdoor measurements. As a result of this development, the first module with automated assembly process of the secondary optics could be manufactured. The highest outdoor efficiency measured for this kind of module is 29.1 %, which is the highest module efficiency achieved at the Fraunhofer ISE so far.