Laser spectroscopy of NV- and NV0 colour centres in synthetic diamond

Abstract

In this paper, we analyse the prospects for using nitrogen-vacancy centre (NV) containing diamond as a laser gain material by measuring its key laser related parameters. Synthetic chemical vapour deposition grown diamond samples with an NV concentration of ~1 ppm have been selected because of their relatively high NV concentration and low background absorption in comparison to other samples available to us. For the samples measured, the luminescence lifetimes of the NV- and NV0 centres were measured to be 8±1 ns and 20±1 ns respectively. The respective peak stimulated emission cross-sections were (3.6±0.1)×10-17 cm2 and (1.7±0.1)×10-17 cm2. These measurements were combined with absorption measurements to calculate the gain spectra for NV- and NV0 for differing inversion levels. Such calculations indicate that gains approaching those required for laser operation may be possible with one of the samples tested and for the NV- centre

Optical gain in NV-colour centres for highly-sensitive magnetometry: a theoretical study

“…3 for different Rabi frequencies as a function of the pumping rate. The calculations are for a 5 mm long diamond sample with an NV-CC concentration of 2.5 ppm, illuminated with 40 mW of probe power at the wavelength of 710 nm (typical output power for a single-mode laser diode at this wavelength), where the NVemission cross-section is 3.6×10 -17 cm 2 [13]. The calculations are done assuming 60% luminescence quantum yield ( Magnetic field sensitivity is highest at a certain optimum pumping rate for each Rabi frequency (Fig.…”

“…Taking into account that  74~  71 [12,14], and  54 = 21 , the solution for N 2 and N 5 in the stationary case can be written as: [14]): 1/ 7 =1/ 71 +1/ 74 . The radiative lifetime of NV-CC is  rad =13 ns [19] and the reported values of the luminescence quantum yield range between 100% [19] and ~60% [13].…”

“…The power of the probe beam after the sample (P out ), assuming that the intensity of the probe is much less than the saturation intensity of the NV-CC (~0.6 MW/cm 2 at 710 nm [13]), can be written as [20]: = ( ( 2 + 5 )) and then, similar to [18,21]…”

Amplification by stimulated emission of nitrogen-vacancy centres in a diamond-loaded fibre cavity

“…For example, photoionisation could be responsible for the quenching of fluorescence as has recently been described for low-power subdiffractionlimited microscopy using NV − centres [21]. The charge state switching dynamics between negative and neutral charge states of the NV centre due to the NIR wavelengths have also been taken into account in exploring the avenue of direct NV − stimulated emission [22,29,30]. This ionisation induced by NIR wavelengths naturally poses concerns about the realisation of the stimulated emission from NV − centres and its amplification inside a strong optical cavity for NIR wavelengths.…”

Applications of nitrogen-vacancy centers in nanodiamonds for nanoscale thermometry and magnetometry

“…In this experiment, I selected a 590 nm laser excitation so that only the NV − center could be excited and hence the contribution of NV 0 could be eliminated. The absorption spectra of NV 0 center at room temperature shows a strong reduction for wavelengths longer than 575 nm whereas around 500 nm the absorption is very high as reported in [137]. Therefore the use of 590 nm laser should remove the contribution of NV 0 center in the luminescence spectra.…”