Atomic absorption spectroscopy and atomic emission spectroscopy involve visible and ultraviolet light. Circular dichroism spectroscopy measures the absorption of circularly polarized light. Recent years have seen progress in experimental methods, including solid-state NMR spectroscopy and Cryo-Electron Microscopy. This was discovered with X-ray absorption fluorescence spectroscopy (XAFS). This monitoring is usually performed using extractive sampling systems coupled with infrared spectroscopy techniques. This has been confirmed by photoelectron spectroscopy. It is often used in analyzing data from spectroscopy or diffraction. This is an alternative method to the use of nuclear quadrupole resonance spectroscopy. UV/Vis Spectroscopy and X-ray crystallography. This allows the experiment to be run as a variation of nuclear magnetic resonance spectroscopy. Precise measurements at many wavelengths allow the identification of a substance via emission spectroscopy. Voigt profiles are common in many branches of spectroscopy and diffraction. Another technique is functional near-infrared spectroscopy. This forms the basis of infrared spectroscopy. Methods of detection using satellite spectroscopy have also been developed.