  The Liquid Argon Time Projection Chambers (LArTPCs) are a choice for the next
generation of large neutrino detectors due to their optimal performance in
particle tracking and calorimetry. The detection of Argon scintillation light
plays a crucial role in the event reconstruction as well as the time reference
for non-beam physics such as supernovae neutrino detection and baryon number
violation studies. In this contribution, we present the current R&D work on the
ARAPUCA (Argon R&D Advanced Program at UNICAMP), a light trap device to enhance
Ar scintillation light collection and thus the overall performance of LArTPCs.
The ARAPUCA working principle is based on a suitable combination of dichroic
filters and wavelength shifters to achieve a high efficiency in light
collection. We discuss the operational principles, the last results of
laboratory tests and the application of the ARAPUCA as the alternative photon
detection system in the protoDUNE detector.
