Design of a CWDM4 single fiber bidirectional transceiving module based on hybrid integration

With the vigorous development of data centers, optical fiber interconnection technologies have been evolved from multimode optical fiber (MMF) parallel transmission to CWDM4 single-fiber bidirectional (Bidi) transmission. What’s more, requirements for miniaturization of optical transceivers are put forward. This paper studies a CWDM4 Bidi transceiving module based on hybrid integration technology. Six optical interleavers in serial and parallel connection function as the CWDM4 wavelength division multiplexer and demultiplexer, while an optical circulator is designed with the three inputs/outputs at the same side, which helps to realize Bidi transmission. The former is based on integrated optics and the latter is based on micro-optics. Through the hybrid integration of integrated optics and micro-optics technologies, the transceiving module is minimized and can be integrated into a QSFP module.