The goal of the MISSION (Mid Infrared SpectrometerS by an Innovative Optical iNterferometer) project is the development of a portable, robust and low-cost optical interferometer, which enables analysis of molecular species directly on the field and not only in the laboratory. MISSION is an ERC Proof of Concept led by Prof. Giulio Cerullo (Physics Department, Politecnico di Milano, Italy) based on an idea generated in the framework of the ERC Advanced Grant STRATUS. Many fields of chemistry, materials science and biomedicine require the identification of specific molecules and the analysis of their structure and chemical composition. Each molecule is characterized by the vibrations of its constituting atoms, which provide a “fingerprint” enabling its unique identification. The most widespread technique for the recognition of molecules is thus the measurement of their vibrations via light absorption in the mid-infrared wavelength range. The standard instrumentation used for these measurements, the Fourier Transform InfraRed spectrometer (FTIR), is however delicate, bulky and expensive, so that its use is often limited to research laboratories.
Based on a patent from Politecnico researchers, MISSION developed a compact, robust and low-cost FTIR spectrometer which drastically simplifies the mid-infrared light measurement procedure. The optical devices developed in MISSION, to obtain two identical and collinear replicas of a light pulse, consist of a sequence of prisms of birefringent material: when a light pulses crosses this sequence, it is divided in two replicas with orthogonal polarization which propagate in the same direction but with different velocities, thus acquiring a variable delay. With respect to traditional interferometers, this enables to obtain two replicas with excellent delay accuracy and long-term stability.
During its activities, MISSION has developed several birefringent interferometers covering a broad range of wavelengths, from the mid-infrared to the visible, and identified a number of commercial applications where they offer competitive advantages, in terms of performance and price, with respect to existing instrumentation. It is the aim of researchers from Politecnico di Milano to establish a spin off company for the commercialization of this technology, targeting at first scientific research laboratories and then industrial R&D and quality control laboratories, aiming finally at portable instruments. Applications range from environmental monitoring of pollutants to non-destructive analysis of artworks, geological studies for material identification, inspection of fields for quantification of nutrients and molecular analysis of drugs to optimize their efficacy.
