The Lumentum coherent flex-grid tunable co-packaged transmitter and receiver device (TROSA) is self-contained and does not require any external optical or optoelectronic components. The compact package footprint and high performance are enabled by Lumentum highly integrated indium phosphide (InP) optical chip technology, used to realize the laser, modulator, and receiver functionality.

The transmitter comprises full C-band flex-grid narrow-linewidth DSDBR tunable laser, a dual-QPSK Mach-Zehnder (MZ) modulator, Tx driver, polarization multiplexer, and coupling optics. A common laser is used to provide a transmit source to the MZ modulator and local oscillator (LO) source to the co-packaged Rx optical hybrid.

An internal close-coupled 43 GBaud RF driver helps optimize signal integrity to the MZ modulator, and monolithically integrated InP SOA functions on the modulator help compensate for additional optical losses at higher modulation rates (up to DP-16QAM).The modulator output SOA function provides power adjustment and shuttering capabilities, independent of the laser control.

The receiver block combines dual-polarization hybrid PIC to mix the incoming signal with internally generated local oscillator, quad-channel differential linear TIA to provide the O-to-E conversion, and peripheral monitors for signal and total power measurement. The InP hybrid integrates on-chip VOA functions to optimize performance.

Transmit and receive functions are integrated into a single compact fully-hermetic package, with optical interfaces compatible with the industry standard LC connectors.