Polarization independent multifunctional two-section optical amplifier/detector

We report on the fabrication and characteristics of multifunctional two-section polarization independent bulk ridge-waveguide semiconductor optical amplifiers operating in the 1.3 mu m wavelength region. These devices can be used as optically preamplified photodetectors and as high-gain in-line transparent detectors/travelling wave amplifiers. The polarization-independent optically preamplified photodetectors reach overall responsivities of 230 A W-1 or 11500 V W-1 in a 50 Omega system and sensitivities of -28.3 dBm at 1.2 Gbit/s and -24.4 dBm at 3 Gbit/s respectively. As in-line transparent detector/travelling wave amplifier the same devices reach polarization independent fibre-to-fibre gains of 11 dB and detection sensitivities of -27.5 dBm at 1.2 Gbit/s.