Development of a multidimensional luminescence microscope and its application to imaging and spectroscopy of luminescent defects in diamond
File(s)
Author(s)
Jones, Daniel Christopher
Type
Thesis
Abstract
This thesis concerns the development and characterisation of a novel multidimensional luminescence microscope, and its application to diamond defect luminescence. The instrument can resolve luminescence with respect to excitation and emission wavelength, lifetime, and polarisation, providing co-registered image data to support studies of the underlying photo physics or evaluation of (diamond-based) photonics devices. The thesis provides an overview of luminescent defects that have been reported in synthetic and natural diamond. Defect parameters based on absorption and emission spectra, lifetime, polarisation, and orientation in the lattice have previously been studied using a myriad of different instruments, technologies, and methods, making direct comparisons difficult. The instrumentation developed in this thesis enables a systematic characterisation of diamond luminescence to provide information concerning growth, processing of diamonds, and to support new applications such as quantum optics and sensing.
Spectrally resolved fluorescence lifetime imaging microscopy (FLIM) was implemented using time-correlated-single-photon-counting (TCSPC) with stage scanning. This could be combined with hyperspectral imaging, which also provides a rapid means to identify spectral and spatial regions of interest. A novel electronically tuneable, ultrafast excitation source was developed and utilised for (polarisation-resolved) photoluminescence emission and excitation (PLE) spectroscopy/imaging, and for hyperspectral imaging and FLIM. For the analysis of luminescence lifetime data, both iterative fitting and phasor analysis were used.
The instrument was applied to synthetic diamonds containing nitrogen and silicon vacancies, and to natural diamonds presenting a range of defects. This enabled separation of defects based on their relative concentrations through FLIM, revealed complex decays caused by quenching, and fundamental measurements of the SiV- defect. These have applications ranging from understanding the photo-physics of defects to better apply them to quantum applications, to determining the origin of diamonds based on their spatial distribution of defects.
Spectrally resolved fluorescence lifetime imaging microscopy (FLIM) was implemented using time-correlated-single-photon-counting (TCSPC) with stage scanning. This could be combined with hyperspectral imaging, which also provides a rapid means to identify spectral and spatial regions of interest. A novel electronically tuneable, ultrafast excitation source was developed and utilised for (polarisation-resolved) photoluminescence emission and excitation (PLE) spectroscopy/imaging, and for hyperspectral imaging and FLIM. For the analysis of luminescence lifetime data, both iterative fitting and phasor analysis were used.
The instrument was applied to synthetic diamonds containing nitrogen and silicon vacancies, and to natural diamonds presenting a range of defects. This enabled separation of defects based on their relative concentrations through FLIM, revealed complex decays caused by quenching, and fundamental measurements of the SiV- defect. These have applications ranging from understanding the photo-physics of defects to better apply them to quantum applications, to determining the origin of diamonds based on their spatial distribution of defects.
Version
Open Access
Date Issued
2021-04
Date Awarded
2021-07
Copyright Statement
Creative Commons Attribution NonCommercial Licence
License URL
Advisor
French, Paul
Dunsby, Christopher
Neil, Mark
Sponsor
Engineering and Physical Sciences Research Council (EPSRC)
Grant Number
EP/L015315/1
Publisher Department
Department of Physics
Publisher Institution
Imperial College London
Qualification Level
Doctoral
Qualification Name
Doctor of Philosophy (PhD)