Swept-wavelength lasers based on GaSb gain-chip technology for non-invasive biomedical sensing applications in the 1.7–2.5 μm wavelength range

Abstract

The infrared spectral region beyond 1.7 μm is of utmost interest for biomedical applications due to strong overtone and combination absorption bands in a variety of important biomolecules such as lactates, urea, glucose, albumin, etc. In this article, we report on recent progress in widely tunable swept-wavelength lasers based on type-I GaSb gain-chip technology, setting a new state-of-the-art in the 1.7 – 2.5 μm range laser sources. We provide an application example for the spectroscopic sensing of several biomolecules in a cuvette as well as an experimental demonstration of a non-invasive in-vivo sensing of human serum albumin through the skin.