Chemical Identification Through Packaging Material Using Safe Raman Spectroscopy

Jun Zhao, Jack Zhou, Katherine Bakeev, Sean Wang
B&W Tek, Delaware, United States

Keywords: Chemical Identification, Raman Spectroscopy, Laser,

A new Raman measurement method is presented that expands the applicability of Raman to See_Through diffusely scattering media such as opaque packaging materials, as well as to thermolabile, photolabile, or heterogeneous samples. Traditional Raman fiber optics probes employ a focused design similar to confocal microscopes. This confocal design has the advantage of maximum throughput. However, when the container diffuses the light strongly, light can no longer be focused inside the container, the confocal approach loses its effectiveness. The See_Through Raman configuration illuminates and collects the Raman scattered light from a large sample area with enhanced throughput. This greatly increases the effective sampling depth, allowing the measurement of material inside visually opaque containers. The large area also has the additional advantage of preventing sample damage by reducing the power density, as well as improving accuracy by eliminating heterogeneous effect. With its high throughput design, the See_Through analyzer provides identity of chemicals through thick packaging material in seconds. Alternatively, a range of accessories can be used in the confocal configuration for different applications including microscopy and stand-off Raman. This flexibility makes the See_Through Raman a suitable technique for a variety of applications, from material ID to demanding research.