To operate wind turbines safely and efficiently, condition monitoring for the main components are of increasing importance. Especially the lack of access to offshore installations increases inspection and maintenance costs. The current work at Fraunhofer IZFP Dresden in the field of monitoring of wind turbines is focused on the development of a condition monitoring system for rotor blades. A special focus lies on the application of optical technologies for communication and power supply. It is not possible to introduce electrical conductors into the rotor blade since it might cause tremendous damages by lightning. The monitoring concept is based on a combination of low frequency integral vibration monitoring and acoustic monitoring techniques in the frequency range between 10 and 100 kHz using guided waves. A joint application of acousto ultrasonics and acoustic emission techniques will be presented. Challenges and solutions of such a field test like sensor application, data handling and gathering as well as temperature variation are described.© (2011) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.