Optimized design and fabrication of high-speed and high-radiance InGaAsP/InP DH LED in the 1-µm wavelength region

Design and fabrication of an InGaAsP/InP double-heterostructure (DH) light-emitting diode (LED) with a monolithic lens, Which exhibits high-speed and high-radiance performance, have been presented. Dependences of operating characteristics such as the coupled power, the current-light linearity and the cutoff frequency on the LED, and the fiber structural parameters, have been analyzed, modeled, and applied to complete an optimal design. It has been found that a high magnification lens allows one to maximize both the coupled output power and the response speed. LED'S coupled to 50-µm core 0.2-NA graded-index fiber have been fabricated at the wavelengths of 1.15, 1.3, and 1.5 µm. A significant improvement has been achieved particularly in the cutoff frequency, and the maximum value of 120 MHz at the current of 100 mA has been realized at 1.3-µm wavelength without reduction of the coupled power (35 µW). High-speed and high-power performances of these diodes are promising for their application to high bit-rate transmission systems.