A symmetric double-core InGaAlAs waveguide photodiode for hybrid integration on optical platforms

A symmetric InGaAlAs waveguide photodiode for low cost modules is investigated. A high responsivity of 0.95 A/W and a low dark current after 1900 hours aging of 300 pA are demonstrated. In this paper, we optimize the symmetric doublecore structure for higher responsivity while maintaining a wide coupling tolerance at a low operating voltage. We also describe the use of a surface passivation technique to achieve low dark current operation over a wide temperature range and after aging at 200 C.