Monolithic Tunable Interferometric Transmitter (TunIT) in Indium Phosphide

Tunable chip-scale optical transmitter devices have revolutionized the pluggable module telecom market, by enabling excellent performance with great cost and size reduction. In this paper, we report on a novel patented tunable transmitter device, based on a dual-output tunable laser, and a pair of modulators, which are interferometrically combined (Tunable Interferometric Transmitter, TunIT). The dual-output laser is based on a Y-branch device architecture, and it utilizes high-reflectivity coating on the back facet. This device exhibits 50-nm tuning range and >40-dB side mode suppression ratio, as well as allows for chirp control. Transmission experiments at 10 Gbps through 75 km of SMF-28 fiber validate its performance. A tunable optical subassembly module with the TunIT device has also been demonstrated.