PIN/Preamp receiver modules for 40-Gb/s optical communication systems

The PIN/Preamp receiver modules suitable for 40 Gb/s optical communication systems are presented. The waveguide PIN photodiodes with a polarization insensitive spot size converter and a GaAs pHEMT traveling wave amplifiers (TWA), which have a typical transimpedance of 150 ohms and a linear operating output voltage more than 700 mVpp, have been assembled in hermetic sealed compact packages. The receiver modules have the responsivity greater than 0.72 A/W, the polarization dependent loss less than 0.2 dB in the wavelength range from 1510 nm to 1620 nm, 45 GHz bandwidth, and the input equivalent noise current density less than 15 pA/sqrtHz. The wide eye opening has been confirmed at the average optical input power of -12 dBm in both 40 Gb/s RZ and NRZ data format. The sensitivity less than -11 dBm has been achieved at BER = 1 x 10^-9 in 40 Gb/s PRBS 2^7-1 NRZ signal. These results indicate that this receiver module can be used not only in long haul application but also in the very short haul application.