Optical sensors based on quantum light need to work even in the presence of imperfections. Here we discuss how to address the presence of noise by measuring multiple parameters at once: those we seek to monitor and those linked to the imperfections. Our method is applied to the investigation of the optical activity of sugary solutions limited by reduced visibility. These studies introduce multiparameter estimation as a viable approach to allow for robust operation of quantum sensors as they are developed from fundamental research to technology.

Quantum photonics has demonstrated its potential for enhanced sensing. Current sources of quantum light states tailored to measuring allow one to monitor phenomena evolving on timescales of second order. These are characteristic of product accumulation in chemical reactions of technological interest, in particular those involving chiral compounds. Here we adopt a quantum multiparameter approach to investigate the dynamic process of sucrose acid hydrolysis as a test bed for such applications. The estimation is made robust by monitoring different parameters at once.

The most meaningful spectral components in laser-induced fluorescence (LIF) spectra for several different commercial plastics have been individuated and used to automatically discriminate among different plastic materials and between plastics and complex organic materials, such as woods. Starting from LIF measurements on known samples, a number of significant wavelengths have been identified by principal component analysis (PCA). These have been used to produce intensity ratios functional to the discrimination. Threshold values for such ratios have been individuated in order to obtain an automatic recognition of plastics. The work done has been preparatory to the design and development of a multispectral imaging LIF system for fast detection of plastic debris in a post-blast scene.

We study the synthesis and characterization of an innovative TEOS-based composite coating, which could improve previous formulations used in the field of monument conservation. The proposed coating is composed by a tetraethoxyorthosilicate matrix (TEOS), containing an elasticiser [hydroxyl-terminated polydimethylsiloxane (PDMS-OH)] and a non-ionic surfactant (n-octylamine). The specific self-cleaning and antifouling properties are obtained by the addition of different kinds of nanofillers: the commercial TiO₂ nanoparticles, plus two different silica nanocontainers, loaded with the commercial biocide 2-mercaptobenzothiazole. Through a multi-analytical approach, we evaluate the effect of the nanoparticles concentration on the coatings drying rate, on the variation of their visual aspect and textural properties. Our results show that the addition of the silica nanocontainers at 0.05% (w/v) in sol does not change the color of the coating and reduces the formation of cracks after drying. Moreover, the coating charged with nanocontainers undergoes slower drying, thus improving its penetration into the pores of the treated surface. Further tests of photocatalytic and biocidal properties of this new product on different lithotypes and their potential interactions are in progress.