Features four high bandwidth Mach-Zehnder modulators integrated with four lasers (1270, 1290, 1310, and 1330 nm) and a CWDM multiplexer, with each channel operating at up to 28 Gbps. The L-PiC operates on a standard single mode optical fiber and includes integrated tap detectors for fiber alignment, system initialization and closed-loop control. A single fiber aligned to the output edge coupler of this 4.1 x 6.5 mm die is the only optical requirement for integrating this device into QSFP28 transceiver applications. The preferred polarization for all optical I/O is TE. A bidirectional coupler on the multiplexed output facilitates fiber coupling and monitors output power via an integrated photodiode.