Novel snapshot hyperspectral imager based on diffractive elements

We present a novel approach for hyperspectral snapshot imaging. Compared to methods containing Fabry-Perot or absorption filters on each of the sensors pixels our approach relies on diffractive optics. The sensor can be realized in a particularly cost-effective and simple way. Another advantage is the possibility of a flexible adaptation to the respective measurement task. The spatio-spectral resolution and also the spectral measuring range can be adjusted and even varied over the sensor. Therefore, it becomes possible to measure certain parts of the scene with high spatial resolution and other parts with high spectral resolution or a different wavelength range. In initial tests, the system was able to detect spectral shifts of less than two 0.5 nm, within a measuring range of 190 nm. Besides potential applications in medicine or agriculture, the system can also be used in surface metrology. For this purpose, we present the realization of an area-based snapshot chromatic confocal sensor, which can perform 2.5D measurements with only one image acquisition.