Multi-pass light amplification for tomographic particle image velocimetry applications

The light source budget is a critical issue for tomographic particle image velocimetry (Tomo-PIV) systems due to its requirement for large illuminated volume and imaging at small apertures. In this work, a light amplification system based on the multi-pass concept is investigated for Tomo-PIV applications. The system design is performed on the basis of a theoretical model providing an estimation of the most important system parameters and above all the amplification gain. The multi-pass light amplification concept is verified experimentally by measuring the scattered light intensity across the illuminated volume. The results demonstrate a gain factor of 7 and 5 times in comparison with the single-pass and double-pass illumination approaches, respectively.