Transform your phone into a light spectrometer that measures dominant wavelength (nm), frequency (THz), and period (fs) of colored light. Point your camera at a white surface illuminated by your target light, and get instant nanometer-precise readings. Acquire full spectrum analysis of LEDs, lamps, lasers, solar or grow lights, and just about any type of luminaire from ultra-violet through the visible and near-infrared! This. A smartphone spectrometer is a device that disperses complex (multicolored) light into distinct "spectral lines", separating it into its component colors. Accurate wavelength measurement is crucial in fields like physics, chemistry, astronomy, and engineering. DOMINANT WAVELENGTH Dominant.