Anagrafe della ricerca

MIRABILIS aims to design, simulate, and experimentally demonstrate a Mid-Infrared (MIR) single-pixel sensor enabling tissue imaging in reflection mode at the Amide-II wavelength region. The sensor addresses the challenging goal by pairing two forefront advanced technologies within a small-footprint Photonic Integrated Circuit (PIC): detectorless, optical-feedback-based imaging in Quantum Cascade Lasers (QCL) and scanless single-pixel compressed sensing. Optical feedback allows for detectorless imaging, inasmuch the illumination (laser) source acts also as the detector of the radiation backscattered by the target. The intensity and phase of that field carry information about the real and the imaginary dielectric susceptibility of the target. The feedback signal can be analyzed via voltage change at the laser terminals. Removing the need of a separate detector for sensing is especially interesting in the MIR, where detectors are neither cheap, compact nor particularly sensitive. This would be the first time that optical feedback imaging in MIR QCLs would be integrated in PICs. Being the QCL a point-like detector, conventional imaging proceeds via raster-scanning the target surface, thus adding mechanical and scattering noise to the increased complexity of the setup. On the contrary, scanless imaging is achieved by illuminating the target via a sequence of randomly distributed light patterns. The feature of the target to be imaged is recovered by analyzing the light intensity collected by a bucket detector via optimized compressed sensing algorithms, thus performing Single-Pixel Imaging (SPI). An Artificial Intelligence approach to SPI based on Deep Neural network will be developed to allow for real time imaging. Spectral features of the Amide-II absorption band around 1600 1/cm are considered diagnostically relevant signatures for important pathologies like epithelial cancers [BAK18]. Even if a monochromatic image cannot provide discriminatory information, it is common practice in automated spectroscopy to consider only few wavelengths of the collected spectra corresponding to relevant spectral signature [BAS14]. New techniques like multiwavelength MIR microscopy will translate direct imaging of a sample tissue into medical practice. The MIR SPI in PIC at 1600 1/cm addressed by MIRABILIS delivers the first channel of a modular device for multispectral and multimodal miniaturized probe appealing for on-sample sensing, including healthcare applications, e.g., in local or endoscopic probes, or surgical field real-time inspection, (overcoming intraoperative biopsies and histopathology assessment.) The project is relevant for the advancement of knowledge in the field of physics, chemistry, and engineering, it addresses ambitious goals and takes innovation challenges in laser dynamics, optical circuit integration and molecular spectroscopy.