To illustrate the potential variations introduced by “extra” excitation energy, figure 11A shows the fluorescence emission peaks from sample 15 (extracted from the 3D fluorescence spectra of this sample containing the 480 nm band) at 365, 405, and 435 nm excitation energies. These are the three emission peaks measured from the GIA LWUV lamp (365 nm being the strongest). The spectra were processed to produce equivalent colors by conversion to equivalent CIE L*a*b* color values using GRAMS AI software (including artifact removal, 2° viewing angle, and CIE D65 illumination; all spectral intensities were scaled up 30× to facilitate color reproduction). The fluorescence peak generated by 365 nm excitation is centered at 520 nm, producing a green color with a slightly yellow tint, whereas the fluorescence peaks caused by 405 and 435 nm excitation energies are shifted up to ~545 nm with a tail extending beyond 750 nm, adding an orange-red component to the yellowish green fluorescence. The strong yellow fluorescence of this diamond under the conventional gemological UV lamp is a mixture of the three emission colors from these LW-UV excitation peaks. Under a “pure” 365 nm LED source, this diamond shows a yellowish green fluorescence. While it would be ideal to illustrate this effect with photos, we could not achieve a long enough exposure to photograph the fluorescence.
To illustrate the potential variations introduced by “extra” excitation energy, figure 11A shows the fluorescence emission peaks from sample 15 (extracted from the 3D fluorescence spectra of this sample containing the 480 nm band) at 365, 405, and 435 nm excitation energies. These are the three emission peaks measured from the GIA LWUV lamp (365 nm being the strongest). The spectra were processed to produce equivalent colors by conversion to equivalent CIE L*a*b* color values using GRAMS AI software (including artifact removal, 2° viewing angle, and CIE D65 illumination; all spectral intensities were scaled up 30× to facilitate color reproduction). The fluorescence peak generated by 365 nm excitation is centered at 520 nm, producing a green color with a slightly yellow tint, whereas the fluorescence peaks caused by 405 and 435 nm excitation energies are shifted up to ~545 nm with a tail extending beyond 750 nm, adding an orange-red component to the yellowish green fluorescence. The strong yellow fluorescence of this diamond under the conventional gemological UV lamp is a mixture of the three emission colors from these LW-UV excitation peaks. Under a “pure” 365 nm LED source, this diamond shows a yellowish green fluorescence. While it would be ideal to illustrate this effect with photos, we could not achieve a long enough exposure to photograph the fluorescence.
การแปล กรุณารอสักครู่..
