GaSb-Based Swept-Wavelength Lasers for Spectroscopic Sensing Applications in the 1.7–2.5 Micron Spectral Range

Abstract

1.7-2.5 micron spectral region is particularly interesting for spectroscopic sensing due to the presence of strong and molecule-specific ro-vibrational absorption bands. These absorption bands correspond to the first overtone of the C-H stretching vibrations and the combination of stretching and bending vibrations of C-H, N-H and O-H bonds, acting as a unique molecular fingerprint for sensing applications and can be read by means of direct photon-phonon (target molecule vibration) interaction. This provides an opportunity for laser based spectroscopic sensing for both gases and liquids. In the field of biomedical application, laser-based sensing of critical biomolecules such as glucose, lactate, urea, serum albumin as they provide key insights into the person's metabolism as well as allow tracking patient's condition in case of difficult chronic diseases such as diabetes, chronic renal failure or act as an important marker in case sepsis.