Error-Free Loopback of a Compact 25 Gb/s × 4 ch WDM Transceiver Assembly Incorporating Silicon (De)Multiplexers with Automated Phase-Error Correction

We propose (de)multiplexers based on tunable cascaded asymmetric Mach-Zehnder interferometers to exclude necessity of highly-scaled expensive Si process by fully-automated fabrication error correction. Incorporating two sets of (de)multiplexers in a 12 × 12 mm transceiver assembly with modulators, photodiodes, drivers, and TIAs, we demonstrate an error-free 25 Gb/s × 4 ch loopback communication.