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Lawrence Wu

PhD Title: Identification of defects in diamond via optically-detected magnetic resonance

PhD Supervisor: Dr. Ben Green,Prof. Mark Newton

Sponsor: De Beers Technology; China Scholarship Council(CSC)

Synopsis of research: Electron paramagnetic resonance is a powerful method to study defects in diamond, however, EPR is not efficient as optical measurement due to its complex operation and limitation of unpair electron spin. In order to explore new defects and study EPR inactive systems in diamond, we tend to use optically-excited EPR and ODMR to study some unknow features in diamond. In our recent research, we found a doubly charge state of SiV center(SiV2-) and some unreported absorption line possibly related to SiVN. In some cases, light excitation can drive intersystem crossing and make EPR inactive system active, lead to the EPR inactive defect become detectable via optically-excited EPR. Moreover, the ODMR provide an efficient way to directly read out EPR signal through fluorescence. Utilizing the two techniques, it expected to detect new defects and more charge state spin of defect. Hopefully, my work can help ODMR become a novel technique applying in discrimination of diamond.


2019-present: PhD in Physics, University of Warwick

2016-2019: MSc in Gemmology China University of Geosciences, Beijing

2012-2016: BSc in Gemmology and Material Science, China University of Geosciences, Beijing

2014-2015: Award Gemmology Diploma of the Gemmological Association of Great Britain(FGA)

Employment history

2017-2019: General assistant of chief scientist (internship)

National gems & jewelry technology administrative Center(NGTC), Beijing, China


2015 Second Prize, Diamond Identification Competition

2016 Outstanding Graduates

2018 First class academic scholarship

2018 Merit Student

2019 The first prize of Postgraduate Academic Report Competition


China international gems & jewelry academic conference. Poster “Application of Fluorescence Lifetime Attenuation Curve in CVD Synthetic Diamond Testing”, Nov 2019.


[1] B G Breeze, C J Meara, X X Wu, C P Michaels, R Gupta, P L Diggle, M W Dale, B L Cann, T Ardon, U F S D'Haenens-Johansson, I Friel, M J Rayson, P R Briddon, J P Goss, M E Newton, B L Green, Doubly-charged silicon vacancy center, photochromism, and Si-N complexes in co-doped diamond. arXiv:2002.01712

[2] Wu Xuxu, Lu Taijin, et al. Gemological characteristics of CVD synthetic diamonds from Ningbo Crysdiam and comparison with IIa companies.Journal of Gems & Gemmology. 2019,21(06):15-23.

[3] Wu Xuxu, Lu Taijin, et al. Observation of Surface Microstructure Of HPHT Synthetic Diamond Crystals. Rock And Mineral Analysis. 2019,38(04):411-417.

[4] Xuxu Wu, Taijin Lu, et al. Observation of etched surface micro-features on HPHT synthetic diamonds using laser confocal microscopy(LCM). Gems & Gemology, Spring 2018, Vol. 54, No. 2,246-248.


Zhang Jian, Lu taijin, Wu xuxu. External Detection Device for Electrical Conductivity Testing of Gemstone Minerals. An Utility Model Patent, China.

Master thesis

Wu Xuxu. Gemological Properties of Domestic Colorless CVD (Chemical Vapor Deposition)Synthetic Diamonds and Hybrid Diamonds. China university of geosciences(Beijing).2019.


EPR & Diamond Group
Department of Physics
University of Warwick

+44(0) 07507585776