Sensing of FWHM and Peak Wavelength for LEDs via Low-cost Filter-array Spectrum Sensor

Peak wavelength and full-width-half-maximum (FWHM) are the two important parameters to characterize the spectra of monochromatic LED lights. In this work, a low-cost miniature filter-array spectrum sensor for accurate LED measurement is proposed. For mapping the data from the outputs of the filter-array spectrum sensor to the measurement parameters of peak wavelength and FWHM, Gaussian curves are used as the basis functions to facilitate the estimation. In addition, particle swarm optimization (PSO) is utilized for searching the optimal center locations and the widths of the Gaussian basis functions. The resulting measurement accuracy is competitive to a professional optical spectrometer.