High-responsivity low-dark-current InGaAlAs waveguidephotodiode with a symmetric double-core for optical access networks

Abstract

A symmetric InGaAlAs waveguide photodiode for low cost optical hybrid integration is designed and fabricated. High responsivity of 0.95 A/W and coupling tolerance of ±2.6 µm, obtained by optimising the double core structure are demonstrated. Dark current as low as 300 pA is achieved by using surface passivation.