Low-cost optical transceivers for access networks

Optical access networks such as fiber-to-the-home (FTTH), fiber-to-the-building (FTTB), or fiber-to-the-curve/cabinet (FTTC/K) are essential to meet future demands for high-speed, high-quality information networks. To establish such optical access networks, low-cost, high-performance, and compact optical transceivers are the key component. Generally the optical transceiver for these systems should provide wavelength-division multiplexing (WDM) functions for 1.3-μm and 1.5-μm wavelengths. The optical transceiver sometimes requires Y-branching for the 1.3-μm wavelength for time-compression multiplexing (TCM) signals. Recently, optical hybrid integrated devices have been used to build high-performance and compact transceivers for such systems. An optical transceiver for FTTH applications is shown. It enables 1.3-μm bidirectional TCM signal transmission and 1.3-μm/1.5-μm WDM functions. This transceiver contains the following innovative technologies to achieve the low-cost target: PLC platform and passive alignment of the optical axis; lensless coupling with planar-lightwave-circuits (PLC) with a spot-size converter integrated laser diode and two waveguide photodiodes; and simplified optical connectors (receptacles)