Pergam OS UVD uses laser radiation to remotely detect and analyze oil films on water surfaces. A pulsed ultraviolet semiconductor laser illuminates the water from up to 40 meters away, causing oil molecules to emit fluorescent light at wavelengths specific to each compound. An optical receiver captures the fluorescent signal and sends the data to the processing unit. Spectral analysis enables the detector to identify a range of hydrocarbons, including crude oil and diesel, even in ultra-thin films starting at 1 µm thick.