Novel rear-illuminated 1.55 μm-photodiode with high wavelength selectivity designed for bi-directional optical transceiver

A novel rear-illuminated pin-photodiode sensitive to only the wavelength of 1.55 μm-band has been successfully developed. This photodiode has an InGaAs absorption layer and double InGaAsP filter layers. The responsivity at the wavelength of 1.55 μm was higher than 0.95 A/W, while the responsivity at the wavelength of 1.3 μm was less than 0.005 A/W. The wavelength selectivity between 1.3 μm and 1.55 μm was as high as 23 dB. This feature is useful to suppress optical crosstalk from a 1.3 μm transmitter to a 1.55 μm receiver. Therefore, this photodiode is promising for the receiver of 1.3/1.55 μm bi-directional optical transceiver modules. A bidirectional transceiver module has been constructed using this photodiode to confirm the fundamental operation. The high receiver sensitivity of -35.5 dBm at B.E.R.(Bit Error Ratio)=10^-10 was demonstrated at 156 Mbps full-duplex operation