I have been using optical spectroscopy in my research for a few years. I use both visible light spectroscopy (Raman, fluorescence, infrared, Brillouin, black-body radiation, etc) and X-ray spectroscopy (diffraction, radiography, inelastic scattering, Mössbauer, X-ray fluorescence, and X-ray absorption) in my research. The wavelength of light that I use in my research ranges from 0.001 nm to 1000 nm.