Fluorescence and absorption patterns in diamond at low temperatures

Anna Mani

Juna Sathian, Jonathan Breeze, Ben G. Breeze +3 more

Here we report the room-temperature and low-temperature absorption spectroscopy (UV-VIS-NIR), and electron paramagnetic resonance spectroscopy (EPR) conducted over a range of chemical vapour deposition (CVD) grown diamond samples. Room temperature absorption and fluorescence studies are shown. We also compared the room-temperature spectra with the experimental results conducted at 80 K. Finally, we used these data to calculate the density of NV in these samples that is responsible for the maser action. The number of NV defect centres is crucial since the total available number of NVs that are useful for maser are limited by the hyperfme coupling with nitrogen. From our previous studies, an NV concentration that lies between 0.2 to 2 ppm will offer the best solution in terms of pumping efficiency and uniform pumping rate for maser.

Victor S. Vavilov, A. A. Gippius, E.A. Konorova

A. Dräbenstedt, C. Tietz, Fedor Jelezko +3 more

Low temperature fluorescence excitation spectroscopy was carried out on single , nitrogen vacancy defect centers.At temperatures below 90, K; the fluorescence intensity of individual centers drastically diminishes because of the population of a metastable singlet state in near resonance with the .optically excited state.Low temperature fluorescence excitation spectroscopy , down to 5 K becomes possible via deshelving of this state with a second laser source.Surprisingly individual centers reveal low temperature fluorescence excitation line widths around 0.6 meV.

A. Dräbenstedt, L. Fleury, C. Tietz +4 more

Individual nitrogen-vacancy defect centers have been investigated by low-temperature confocal microscopy and fluorescence excitation spectroscopy. At temperatures below 90 K the fluorescence intensity of individual centers drastically diminishes because of the population of a metastable singlet state in near resonance with the optically excited state. Low-temperature fluorescence excitation spectroscopy down to 5 K becomes possible via deshelving of this state with a second laser source. Surprisingly individual centers reveal low-temperature fluorescence excitation line widths around 0.6 meV, more than two orders of magnitude larger than expected from previous high resolution laser spectroscopy on bulk samples.

Estela Pereira, T. Monteiro