Handheld Phosphorescence Detector

Phosphorescence-based authentication and trace sensing in a handheld.

A keyfob-size handheld detector that identifies security inks and taggants by their phosphorescent response — used by customs and law enforcement to verify authenticity and duty-paid status, with the same technology applied to non-invasive glucose sensing.

We developed a handheld keyfob-size detector for detecting and identifying the type and concentration of security inks on documents and products. Able to operate reliably and accurately in everyday environments and used by customs and law enforcement, these handheld sensors illuminate the target with pulses of high intensity infrared light at various wavelengths, then detect the tiny quantity of light which is returned (by phosphorescence) at a different wavelength. The light returned is classified by response amplitude and decay time, to identify the varieties of security ink present. Mixtures of ink are proprietary and can be used to prove product or document authenticity, and verify “duty paid” stickers. Because only a low concentration of ink is used, and the phosphorescence decays in a few milliseconds, the electronic design is challenging, as it must be able to measure a tiny signal immediately after the optical and electronic components have been saturated by the large transmission. The detector is designed to be low-power so can be used hundreds of times before recharging, and has audio and visual feedback to the operator. The same technology has been used for non-invasive glucose level detection for diabetics.

Core Capabilities

Trace-level phosphorescence detection engineered for handheld, field-grade authentication.