Challenges in the Miniaturization of Mid-IR Sensors Fully Integrated on Si

The Mid-IR spectral range (2.5 μm up to 12 μm) has been considered as the paradigm for innovative silicon photonic devices. In less than a decade, chemical sensing has become a key application for Mid-IR silicon photonic devices because of the growing potential in spectroscopy, materials processing, chemical and biomolecular sensing, security and industry application. Measuring in this spectral range, usually called fingerprint region, allows to address a unique combination of fundamental absorption bands order of magnitude stronger than overtone and combination bands in the near IR. This feature provides highly selective, sensitive and unequivocal identification of the chemicals.