Abstract: A multispectral imaging apparatus includes a processor and a plurality of sets of light-emitting diodes (LEDs) in communication with the processor. One or more first sets of LEDs has a wavelength in a visible range, and one or more second sets of LEDs has a wavelength in a short wavelength infrared range. The apparatus includes a truncated source cone through which light from the plurality of sets of LEDs is directed onto a surface and through which light reflected off of the surface is received. The apparatus also includes a visible light camera configured to capture a first image of the surface based on reflected light that originates from the one or more first sets of LEDS. The apparatus further includes an infrared light camera and configured to capture a second image of the surface based on reflected light that originates from the one or more second sets of LEDs.

Abstract: Optically trapped specimens (typically nanoparticles having diameters between 1 and 50 nm) are excited with an optical beam so as to induce vibrations in the specimens. A trapping optical beam and the excitation optical beam can produce vibrations based on a difference frequency based on the trapping optical beam and the excitation optical beam. Scattered optical radiation as a function of modulation frequency can be recorded and used to identify or characterize the specimen.

Abstract: Optically trapped specimens (typically nanoparticles having diameters between 1 and 50 nm) are excited with an optical beam so as to induce vibrations in the specimens. A trapping optical beam and the excitation optical beam can produce vibrations based on a difference frequency based on the trapping optical beam and the excitation optical beam. Scattered optical radiation as a function of modulation frequency can be recorded and used to identify or characterize the specimen.