Analysis of new pharmaceutical compounds is essential to ensure the composition and safety of drug formulations. The speed with which new compounds can be characterized increases with a downsized Raman spectroscopy system developed at Texas A&M University.

The instrument is designed to replace bulky benchtop equipment with a tiny photonic chip and to provide high-throughput, real-time chemical characterization at least 10 times more sensitive than conventional benchtop Raman spectroscopy systems. The design features aluminum nitride optical waveguides, prepared by reactive Aluminum nitride optical waveguide carries the laser beam to a test sample. Scattered light reveals the sample’s Raman molecular fingerprint. Source: Pao-Tai Linsputtering deposition and complementary-metal-oxide semiconductor processes, for organic compound analysis. The waveguide material generates a low Raman background signal and is less likely to interfere with the signal coming from a test sample.

The performance of the waveguide sensor was evaluated by transporting a laser beam through the waveguide and measuring the Raman spectra of benzene derivative mixtures consisting of benzene, anisole and toluene. The ability to distinguish each molecule type within the sample on the basis of Raman spectra was demonstrated with a sensitivity surpassing that of conventional Raman benchtops.

The structure of the optical waveguides is conducive to high-throughput, real-time chemical sensing needed for drug development, and many of these devices can be loaded onto a single photonic chip.