Excimer laser based photoluminescence device for diamond identification

Abstract

Surface excitation using deep ultra-violet (DUV) laser light has been applied to diamond which reveals growth structures, as well as photoluminescence originating from crystallographic defects features. This valuable information can aid in distinguishing natural diamonds from their lab-grown counterparts and non-diamond gemstone materials. In this research, we presented a dual photoluminescence imaging and spectroscopy setup using a 193nm argon fluoride (ArF) excimer laser, chosen for its above diamond bandgap (5.5eV) photon energy and high average power. This setup enables the detection of diamond’s characteristic photoluminescence emission features and growth patterns under room temperature conditions. Various types of diamonds, including chemical vapor deposition (CVD) as-grown, CVD grownhigh pressure high temperature (HPHT) treated, HPHT-grown, natural diamond and diamond simulant samples were characterized under this setup.