Intensity Rules for the Defect-activated One-Phonon Absorption in Diamond

Nonlinear optical absorption in commercially available diamond crystals containing nitrogen-vacancy (NV) centers is investigated using femtosecond open-aperture Z-scan measurements at a wavelength of 1032 nm. Experiments were performed on a high-purity electronic-grade diamond and on samples with moderate and high NV concentrations. While the undoped crystal exhibits third-order nonlinear absorption, the NV-doped samples show a pronounced saturable absorption response. To elucidate the microscopic origin of this effect, the Z-scan results are analysed in conjunction with linear transmission spectra, which reveal the presence of additional nitrogen-related defect complexes, including H2 ( $\hbox {NVN}^{-}$ ) centers. Although the excitation wavelength is detuned from the principal zero-phonon lines of both NV and H2 defects, it overlaps with the broader near-infrared absorption band associated with vibronic transitions. A quantitative analysis based on an effective two-level model indicates that the observed saturable absorption is most consistently explained by a dominant contribution from H2 defects, while a weaker off-resonant contribution from NV centers cannot be excluded. The extracted parameters, including the linear absorption coefficient and saturation intensity, are supported by a reconstruction of the defect-related absorbance spectrum and by consistency with previously reported nonlinear refractive index data. These results highlight the importance of complex defect environments in determining the nonlinear optical response of NV-doped diamond and provide insight into defect-specific contributions relevant for diamond-based nonlinear and quantum photonic applications.Nonlinear optical absorption in commercially available diamond crystals containing nitrogen-vacancy (NV) centers is investigated using femtosecond open-aperture Z-scan measurements at a wavelength of 1032 nm. Experiments were performed on a high-purity electronic-grade diamond and on samples with moderate and high NV concentrations. While the undoped crystal exhibits third-order nonlinear absorption, the NV-doped samples show a pronounced saturable absorption response. To elucidate the microscopic origin of this effect, the Z-scan results are analysed in conjunction with linear transmission spectra, which reveal the presence of additional nitrogen-related defect complexes, including H2 ( $\hbox {NVN}^{-}$ ) centers. Although the excitation wavelength is detuned from the principal zero-phonon lines of both NV and H2 defects, it overlaps with the broader near-infrared absorption band associated with vibronic transitions. A quantitative analysis based on an effective two-level model indicates that the observed saturable absorption is most consistently explained by a dominant contribution from H2 defects, while a weaker off-resonant contribution from NV centers cannot be excluded. The extracted parameters, including the linear absorption coefficient and saturation intensity, are supported by a reconstruction of the defect-related absorbance spectrum and by consistency with previously reported nonlinear refractive index data. These results highlight the importance of complex defect environments in determining the nonlinear optical response of NV-doped diamond and provide insight into defect-specific contributions relevant for diamond-based nonlinear and quantum photonic applications.

arXiv:2601.12421Scientific ReportsAug 18, 20261 citation

Phonons in diamond crystals

Charles Santori, Raymond G. Beausoleil

Nature PhotonicsDec 22, 20118 citations

Saturable absorption in defect-rich diamond nanophotonics

Christopher Coutts, Nicholas J. Sorensen, Elham Zohari +3 more

Diamond is a leading quantum photonics platform due to its ability to host qubits based on crystal defects such as nitrogen-vacancy centres. Fabricating nanophotonic devices from defect-rich diamond, which underpins many quantum sensing technologies, promises enhanced performance and integrability of diamond quantum sensors. Here we demonstrate microdisk cavities fabricated from defect-rich diamond that support optical modes with high quality factor ( ${Q}\sim7\times10^4$ at $1042\,$ nm) and show that they exhibit saturable absorption. Power-dependent spectroscopy measurements spanning 979 $\,$ nm to 1604 $\,$ nm are used to observe intensity-dependent cavity loss and extract wavelength-dependent absorption coefficients and saturation intensities. At 1047 $\,$ nm, we observe saturation and measure a saturation intensity of $2.1\,(8)\,$ MW/cm $^2$ and an absorption coefficient of $0.53\,(2)\,$ cm $^{-1}$ . These results provide insight into defect-mediated optical loss in diamond nanophotonics and suggest strategies to harness defect-induced nonlinearities in future diamond photonic devices.Diamond is a leading quantum photonics platform due to its ability to host qubits based on crystal defects such as nitrogen-vacancy centres. Fabricating nanophotonic devices from defect-rich diamond, which underpins many quantum sensing technologies, promises enhanced performance and integrability of diamond quantum sensors. Here we demonstrate microdisk cavities fabricated from defect-rich diamond that support optical modes with high quality factor (${Q}\sim7\times10^4$ at $1042\,$nm) and show that they exhibit saturable absorption. Power-dependent spectroscopy measurements spanning 979$\,$nm to 1604$\,$nm are used to observe intensity-dependent cavity loss and extract wavelength-dependent absorption coefficients and saturation intensities. At 1047$\,$nm, we observe saturation and measure a saturation intensity of $2.1\,(8)\,$MW/cm$^2$ and an absorption coefficient of $0.53\,(2)\,$cm$^{-1}$. These results provide insight into defect-mediated optical loss in diamond nanophotonics and suggest strategies to harness defect-induced nonlinearities in future diamond photonic devices.

physics.opticsCross-listedarXiv:2603.11367OpticaMar 13, 20260 citations

Coherent control theory and experiment of optical phonons in diamond

寛弥佐々木, Hiroya Sasaki, Riho Tanaka +7 more

Jun 1, 20180 citations

\hbox {NVN}^{-}

) centers. Although the excitation wavelength is detuned from the principal zero-phonon lines of both NV and H2 defects, it overlaps with the broader near-infrared absorption band associated with vibronic transitions. A quantitative analysis based on an effective two-level model indicates that the observed saturable absorption is most consistently explained by a dominant contribution from H2 defects, while a weaker off-resonant contribution from NV centers cannot be excluded. The extracted parameters, including the linear absorption coefficient and saturation intensity, are supported by a reconstruction of the defect-related absorbance spectrum and by consistency with previously reported nonlinear refractive index data. These results highlight the importance of complex defect environments in determining the nonlinear optical response of NV-doped diamond and provide insight into defect-specific contributions relevant for diamond-based nonlinear and quantum photonic applications.

{Q}\sim7\times10^4

1042\,

nm) and show that they exhibit saturable absorption. Power-dependent spectroscopy measurements spanning 979

\,

nm to 1604

\,

nm are used to observe intensity-dependent cavity loss and extract wavelength-dependent absorption coefficients and saturation intensities. At 1047

\,

nm, we observe saturation and measure a saturation intensity of

2.1\,(8)\,

MW/cm

^2

and an absorption coefficient of

0.53\,(2)\,

^{-1}

. These results provide insight into defect-mediated optical loss in diamond nanophotonics and suggest strategies to harness defect-induced nonlinearities in future diamond photonic devices.