By using impedance (Z) matching circuits in a low-cost transistor outline (TO) CAN package for a 10 Gb/s transmitter, we achieve a cost-effective and small bidirectional optical subassembly (BOSA) with excellent optical transmission waveforms and a > 40% mask margin over a wide temperature range (-10 to 85). We describe a design for Z matching circuits and simulation results, and discuss the advantage of the cost-effective compensation technique.

The 10-gigabit Ethernet passive optical network (10G-EPON) is a promising candidate for the next generation of fiber-to-the-home access systems. In the symmetric 10G-EPON system, the gigabit Ethernet passive optical network (GE-PON) and 10G-EPON will have to co-exist on the same optical network. For this purpose, an optical triplexer (10G-transmitter, 1G-transmitter, and 10G/1G-receiver) for optical line terminal (OLT) transceivers in 10G/1G co-existing EPON systems has been developed. Reducing the size and cost of the optical triplexer has been one of the largest issues in the effort to deploy 10G-EPON systems for practical use. In this paper, we describe a novel small and low-cost dual-rate optical triplexer for use in 10G-EPON applications. By reducing the optical path length by means of a light collection system with a low-magnification long-focus coupling lens, we have successfully miniaturized the optical triplexer for use in 10G-EPON OLT 10-gigabit small form factor pluggable (XFP) transceivers and decreased the number of lenses. A low-cost design of sub-assemblies also contributes to cost reduction. The triplexer's performance complies with IEEE 802.3av specifications.