Linear Cascade GaN-Based Green Light-Emitting Diodes With Invariant High-Speed/Power Performance Under High-Temperature Operation

We demonstrate the performance of linear cascade green light-emitting diode (LED) arrays suited for use in plastic optical fiber (POF) communications in automobiles or harsh environments. With this three-LED array, driven by the constant voltage bias of an in-car battery output (12 V) we obtain high-speed ($\sim$100-Mb/s eye-opening), high-coupling power (0.9 mW), and a very small variation of coupled power versus temperature [$-$ 0.12%$^{\circ}\hbox{C}^{-1}$ at room temperature (RT)] for the whole measured temperature range (i.e., RT to 120 $^{\circ}$ C). Even under high bias current (100 mA) operation, our device can sustain a clear 150-Mb/s eye-opening from RT to 120 $^{\circ}$C. The static and dynamic measurement results indicate that the speed and power performance of this device are less sensitive to variations in ambient temperature than are those of the red resonant-cavity LEDs utilized for POF communication.