Monolithic integrated 4×25 Gb/s transmitter optical subassembly at 1.55 μm

Abstract We report a monolithic integrated 4 × 25 Gb/s transmitter optical subassembly (TOSA) module at 1.55 μ m. The module consists of 4 directly modulated lasers (DMLs) and an arrayed waveguide grating (AWG) with 400 GHz channel spacing. The DMLs and AWG are highly integrated on a 4 mm × 6 mm InP chip which is mounted on an AlN substrate and butterfly packaged. The characteristic of the TOSA module is measured in terms of optical spectra, crosstalk and small-signal frequency response. Data transmission propagating over 3.1 km single mode fiber (SMF) at 25 Gb/s with non-return to zero on–off keying (NRZ-OOK) modulation is explored experimentally. The results show an excellent uniformity of the 4 DMLs, which all reaches 25 Gb/s. The transmission rate up to 100 Gb/s for back-to-back (BTB) and 3.1 km fiber transmission with an error rate of 10−9 is reached. Of great importance, the packaged 4 × 25 Gb/s TOSA module meets the ITU standards very well, showing a promising extension on more channels and higher transmission speed