Analysis on optical properties for various types of light emitting diode

In this paper, comparison on wall-plug efficiency for the infrared (IR) emitter, warm-white LED and multi-chips LED has been studied. The main objective of this work is to provide a specific reference on wall-plug efficiency between various types of LED. Optical measurement is carried out at constant current of 1.0A under ambient temperature of 26.0 ± 1.0^oC. It is found that IR emitter offers the highest wall-plug efficiency (34.5%) compared to warm-white LED (18.4%) and multi-chips LED (29.3%). In addition, influence of forward current on optical power for all the LEDs has also been discussed. As a result, optical power increases with increasing of forward current.