Electrically pumped InGaAsP-InP microring optical amplifiers and lasers with surface passivation

Vertically coupled electrically pumped InGaAsP microring optical amplifiers providing gain at 1550 nm are demonstrated. The microrings provide up to 10 dB of gain at the through-port in pulsed mode. The bias current is used to control the loss in the ring and, hence, the region of operation (under-coupled, critically coupled, transparency, and gain). Sulfur passivation is used to reduce carrier loss due to surface recombination in the active region. The amplifiers are designed for application in cascaded microring optical logic gates in photonic logic circuits.