High speed response InGaAsP/InP DH LED´s in the 1 µm wavelength region

The frequency response of a fiber-coupled LED with a small diameter contact has been studied. It has been shown that the current spreading occurring at the contact edge causes an appreciable response speed reduction. However, this was found to be eliminated by a monolithic lens formed on the LED surface, which can make only the light generated at the center of the contact coupled into a fiber. This technique was successfully applied to fabricate high speed InGaAsP/ InP DH LED´s at wavelengths of 1.15 µm, 1.3 µm, and 1.5 µm. The 1.3 µm LED´s exhibited the -1.5 dB cutoff frequency of 80 MHz, typically at 100 mA current without reduction of the coupled power.