title: Note: design and characterization of an optical light source based on mixture of white and near-ultraviolet light emitting diode spectra.
abstract: An optical light source based on a solid-state lighting technology is designed. Main components of the light source are a phosphor-converted white and a near-ultraviolet (near-UV) light emitting diodes (LEDs), the spectral power distributions (SPDs) of which are mixed using a fiber optic combiner. The near-UV LED is used for improving insufficient SPDs of the white LED at shorter wavelengths of the visible radiation. Stable direct current power supplies are also designed and used to operate each of the LED separately. Three steps of the driving current can be selected by means of serial resistors altered with a commutator at nominal current values of ∼40%, ∼50%, and ∼69%. The light source can be used for many characteristic measurements within the scope of photometry and colorimetry.
authors.affiliation: Optics Laboratory, National Metrology Institute of Turkey (TUBITAK UME), TUBITAK Gebze Yerleskesi, 41470 Gebze, Kocaeli, Turkey. ferhat.sametoglu@ume.tubitak.gov.tr
authors.forename: Ferhat
authors.initials: F
authors.lastname: Sametoglu
authors.forename: Oguz
authors.initials: O
authors.lastname: Celikel