Optical circuits and integrated detectors

Detectors integrated with optical circuits are expected to play an important role as key devices in optical telecommunications. This paper focuses on pin GaInAs detectors monolithically integrated on InP based photonic circuits. Examples of such circuits include coherent receiver and access switch for a high speed local area network. Various detector structures and integrated strategies (butt-joint coupling and evanescent coupling) are reviewed and critically compared. Despite its weaker coupling to the waveguide, it is shown that evanescent field coupled structure is very attractive because of its relative ease of fabrication, good electrical characteristics and flexibility. The most recent results on evanescent field coupled detectors are reported. This includes pin detectors fabricated on both n⁺ and semiinsulating InP substrates