The research activity is based on the techniques of classical and quantum optics to develop standards and measurement methods for photometry and radiometry. The scope in the long run is to secure solid bases for metrology and the International System of Units through the foundations of quantum mechanics and the fundamental constants of physics. Standards and scales are for international comparisons and dissemination inside Italy. The knowledge acquired is transferred to the advantage of Italian industry with particular attention to quantum information and lighting engineering.

In collaboration with Moscow University, we characterised fiber transmission of polarisation entangled states of photons. On the one hand we obtained, for the first time, that different Bell states can be generated simultaneously in type II PDC at slightly different wavelengths. On the other hand we showed how polarisation fiber effects can be compensated in go and back protocols by using a Faraday Mirror. Finally, we have extended these studies to the type I PDC case.
Again with Moscow University we performed a theoretical analysis of the calibration of analog detectors by exploiting PDC. In collaboration with the Università di Milano and Torino we extended to the multi-partite case the scheme based on on/off detectors for reconstructing the statistics of quantum optical states and performed a careful analysis of the uncertainties estimate for this set-up. The feasibility of the Earth-space quantum communication channel was verified in collaboration with Politecnico di Torino and Alenia Spazio through a systematic study of static atmospheric effects in various climatic conditions.

This activity was devoted mainly to Transition-Edge Sensors (TES). TESs based on titanium films have been characterized and bilayers of titanium/gold have been studied to lower the transition temperatures under 100 mK. Single photon counting has been obtained with a 20 µm × 20 µm Ti/Au TES with a transition temperature of 87 mK, demonstrating the peculiar intrinsic energy resolution from 200 nm to 800 nm. Antireflection coatings and cavities have been designed to increase the quantum efficiency of TES. Some commercial RF-amplifiers have been characterized in view of their possible applications to very fast superconducting photodetectors. MgB₂ bolometers have been studied on bulk substrates and SiN membranes. Noise properties have been investigated on MgB₂ films.

In collaboration with the ISC-CNR, we realized a CW source of photon pairs at 1550 nm in a Periodically-Poled LiNbO₃ (PPLN) waveguide. A PPLN waveguide producing photon pairs at (810-1550) nm has been tested as a fiber-coupled heralded single photon source at 1550 nm, with high collection efficiency and brightness due to the guiding structure of the waveguide. In collaboration with the Università dell'Insubria, we developed the theory and performed the first experimental demonstration of ghost imaging realized with intense beams generated by PDC seeded with pseudo-thermal light. In collaboration with NIST (USA), we studied schemes for photon-counting detection at incident photon rates higher than otherwise possible by suppressing the effects of detector dead-time.

The spectrophotometric characterisations of ancient Coptic fabric (collection of Montserrat monastery) has been carried out with the aim of confirming the non-conventional production technology of an interesting violet hue.
At Trento, the Tiresia laboratory has been used to verify a mathematical model for evaluating the effects of road lighting systems in sky luminance: an important environmental aspect known as light pollution. Measurements confirm the validity of the model and give figures for its parameters. The upward lighting emission ratio of a luminaire does not describe the complexity of a town: in Trento the replacement of 30% of the rural luminaires with flat glass devices can increase sky luminance by 8%.

In co-operation with CNR-IEIIT and CSP Innovazione nelle ICT, mathematical algorithms have been implemented for the restoration of old movies. In detail, temporal techniques have been applied to correct defects on successive photograms. Dust and spots have been removed by some adaptative road pattern search. Scratches have been detected and missing information has been retrieved by a probabilistic model based on space locality.