Abstract: An experimental system for measuring properties of the infrared light-emitting diode （RLED） is designed. The relationships of current-voltage, current-light intensity, spectral distribution, angular distribution of luminous intensity and duty-luminous intensity are investigated. As low-cost, high sensitivity and easy operation, the system can be used for physics experiment teaching.

Key words: infrared light-emitting diode （RLED）, luminous intensity, photoelectric conversion, driving circuit