The Fraunhofer Institute for Surface Engineering and Thin Films (IST) will be providing an insight into this key technology for optical sensor technology at the joint Fraunhofer stand at the Laser World of Photonics trade fair in Munich (Hall A2, Stand 415). High-precision interference filters, which are produced using a sputtering process, are at the center of the trade fair presentation. This allows both linearly variable filters with a particularly wide spectral bandwidth and pixel-precise structured filter stacks for specific wavelength ranges to be realized - from the visible (VIS) to the near infrared range (NIR). In the future, systems are conceivable which - depending on the detector - cover the entire spectral range from ultraviolet (UV) to mid-infrared (MIR).
Systems such as the EOSS sputtering platform (Enhanced Optical Sputtering System) are available for production at the Fraunhofer IST. The high precision in filter production allows precisely adapted spectral selection on the camera chip - without complex optical setups.
The elimination of external filter units reduces the size, weight and cost of the systems - an advantage for mobile use, for example. The procedure can be used wherever compact spectroscopy instruments are required.
Interference filters produced using the sputtering process are already being used in hyperspectral imaging, for example in environmental analysis to monitor pollutants or in agriculture to check the condition of plants. The filters are also easy to integrate into existing systems, as no complex integration processes are required.