Phosphor-conversion white light using InGaN ultraviolet laser diode

We fabricated a phosphor-conversion white light using an InGaN laser diode that emits 405nm near-ultraviolet (n-UV) light and phosphors that emit in the blue and yellow regions when excited by the n-UV and blue light, respectively.The relationship of the luminous flux and the luminous efficacy of the white light with injection current was discussed. The luminous flux increased linearly with increasing current above the threshold of the laser diode, and at 80mA injection current, the luminous flux and luminous efficacy were estimated to be 5.7lm and 13lm∕w, respectively. The shift of the Commission International de I’Eclairage coordinates, color temperature, and color rendering index with current are very slight and negligible, which indicates that the blue and the yellow phosphors have an excellent stability and a highly stable white light can be obtained by this way.