High Assembly Tolerance and Cost-Effective 100-Gb/s TOSA With Silica-PLC AWG Multiplexer

A low-cost hybrid-integrated transmitter optical sub-assembly (TOSA) for a 100-Gb/s coarse wavelength division multiplexing (CWDM) transceiver with high assembly tolerance has been demonstrated. We have proposed a novel two-lens configuration for the coupling between distributed feedback laser diodes and a silica-based planar lightwave circuit arrayed waveguide grating to relax the lenses assembly requirement. For this TOSA, the 1-dB assembly tolerances of all lenses are over ±15 μm. Furthermore, we use a flexible printed circuit to connect the interior and exterior of the TOSA for radiofrequency signal transmission instead of the conventional ceramic feed-through box. Finally, a TOSA was packaged with a size of 22 mm × 10.7 mm × 4.5 mm. Error-free transmission over a 10-km single-mode fiber was successfully achieved when all four lanes were driven simultaneously with a total bit rate of 4 × 25.78125 Gb/s at an operating temperature of 25 °C.