Flip-chip planar GaInAs/InP p-i-n photodiode array for parallel optical transmission

A back-illuminated planar GaInAs/InP p-i-n photodiode array with a simple fabrication process was developed for application to parallel optical transmission. Four p-i-n photodiodes were integrated in the array. The average capacitance and dark current were as low as 0.12 pF and 8 pA, respectively, at -5 V. At a 1.55- mu m wavelength, the quantum efficiency of each photodiode was over 80%. The cutoff frequency was 8-10 GHz with four photodiodes when the bias voltage was -3 V and the load resistance was 50 Omega . Crosstalk between channels was -12 dB at the cutoff frequency and -45 dB at 1 GHz.<
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