Photoluminescence Mapping of Optical Defects in HPHT Synthetic Diamond

Abstract

oknown as point defects, absorb visible light to produce color (Collins, 1982). In this way, optical centers give rise to the variety of fancy-color diamonds available in the trade. Optical centers can form as a result of impurities in the diamond (such as nitrogen or boron), deformation of the crystal lattice, missing carbon atoms (vacancies), or a combination of these (Collins, 2003; Breeding and Shigley, 2009). Photoluminescence occurs when an optical center is excited to a higher energy state by the absorption of photons and then returns to its ground energy state, emitting light at a specific wavelength or band of wavelengths (Collins, 1992; Eaton-Magaña and Breeding, 2016). There are currently several hundred known optical centers in diamond that produce photoluminescence (e.g., Collins, 1999; Zaitsev, 2001). Photoluminescence (PL) spectroscopy is a powerful tool used in gemological laboratories to verify whether a specimen is natural or synthetic and determine whether its color origin is natural or due to treatment (Eaton-Magaña and Breeding, 2016). One drawback is