InGaAs dual-pin detector with very symmetric properties for use in coherent optical receivers

A dual InGaAs p-i-n photodiode structure based on metalorganic vapor-phase epitaxy or liquid-phase epitaxy layers grown on planar semi-insulating InP substrates is discussed. The photodetector shows very symmetric properties for the two devices. It is shown that an additional InP p-n junction beneath the photodiodes effectively blocks leakage currents through the substrate and results in dark currents on the order of 100 pA for both of the electrically connected photodiodes.<
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