Abstract: Gemstone grading method including illuminating the gemstone by light having a plurality of spectral components, each modulated according to a spectrally specific modulation (e.g., of intensity, frequency, phase), collecting the light following interaction with the gemstone, extracting from the collected light a set of intensity values for a respective set of modulation parameter values to provide a transmittance spectrum, and an output indicative of the transmittance spectrum (e.g., color, clarity, fluorescence grade).

Abstract: A system for detecting stimulated emission from a material of interest comprising: an excitation source; and an imaging component; wherein, in use, the system is configured to: a) emit excitation radiation from the excitation source for a first time period, the excitation radiation having a wavelength suitable for inducing stimulated emission in the material of interest; b) capture a first image via the imaging component, the first image substantially consisting of a background illumination component and a stimulated emission component; c) stop emitting excitation radiation for a second time period; d) capture a second image via the imaging component, the second image substantially consisting of the background illumination component; e) create a difference image corresponding to the difference between the first and second images, such that the difference image includes any stimulated emission signals from the material of interest.

Abstract: A method of operating an ultrasound imaging system having an array of transducer elements. The method comprises transmitting a plurality of ultrasound signals, each transmission using a different sub-aperture of the array, receiving a plurality of reflected ultrasound signals by a receive array corresponding to each sub-aperture transmission, calculating a coherency factor corresponding to the proportion of coherent energy in the received signals from each sub-aperture transmission and weighting the received output by the calculated coherency factor, and synthesizing all weighted outputs under all different sub-aperture transmissions.