While silica waveguide PLC products have been deployed in various systems and applications, hybrid
integration of semiconductor opto-electronic devices on silica-based planar lightwave circuit (PLC) has become
the mainstream platform for small form factor, low-cost and high volume integrated transceiver modules. One
of the main benefits of hybrid integration is the wafer-scale process, which greatly reduces chip/module size
and assembly cost. This paper reviews the development of this technology, and as an example, presents a
hybrid integrated transmitter with four wavelengths on silica PLC chip for LX4 and 10GbE applications.
Silica waveguide technology transitioned from laboratories to commercial use in early 1990. Since then, various applications have been exploited based on this technology. Tens of thousands of array waveguide grating (AWG) devices have been installed worldwide for DWDM Mux and Demux. The recent FTTH push in Japan has renewed the significance of this technology for passive optical network (PON) application. This paper reviews the past development of this technology, compare it with competing technologies, and outline the future role of this technology in the evolving optical communications.
Low cost and reliable passive components are essential to further span the use of fiber optics and realize the all- optical communication networks. Silica waveguide technology has played an important role in the development of passive components. Devices of 1 X N, 2 X N splitters, and 1.3/1.55 WDMs have been mass-produced for practical applications. Recently, large volumes of array waveguide gratings have also been produced for dense WDM applications. The optical fiber preform manufacturing process, flame hydrolysis deposition is adapted to deposit low loss silica glass on planar substrates (silicon, quartz or alumina ceramics). Photolithography and reactive ion etching is then applied to pattern various types of integrated waveguide circuits. Testing, fiber-connecting, and device packaging follow the circuit fabrication to produce the fiber- pigtailed modules. The technology provides a versatile means of building passive components. In this paper, the manufacturing processes are reviewed and the functions and performance of various circuits are discussed with an emphasis on the current status of the array waveguide gratings.