We report a novel, compact design of high speed Ge photo detector integrated with an echelle demultiplexer on a large
cross-section SOI platform with low insertion loss and low fiber coupling loss. A narrow Ge photo detector waveguide is
directly butt-coupled to a Si waveguide to ensure low loss and high speed operation. With a Ge detector size of only
0.8×15 μm2, the device achieves greater than 30 GHz modulation speed. The results indicate that the device speed is
transit time limited and that the detector performance benefits from the high electron and hole drift velocity of
germanium. The dark current of the detector is less than 0.5μA at -1V. This small footprint high speed Si-based WDM
receiver can be fabricated using CMOS processes and used for multichannel terabit data transmission with low
Recent deployments of fiber-to-the-home (FTTH) represent the fastest growing sector of the telecommunication
industry. The emergence of the silicon-on-insulator (SOI) photonics presents an opportunity to exploit the wide
availability of silicon foundries and high-quality low-cost substrates for addressing the FTTH market. We have now
demonstrated that a monolithically integrated FTTH demultiplexer can be built using the SOI platform. The SOI filter
comprises a monolithically integrated planar reflective grating and a multi-stage Mach-Zehnder interferometer that were
fabricated using a CMOS-compatible SOI process with the core thickness of 3.0 ?m and optically insulating layer of
silica with a thickness of 0.375 ?m. The Mach-Zehnder interferometer was used to coarsely separate the 1310 nm
channel from 1490 and 1550 nm channels. Subsequently, a planar reflective grating was used to demultiplex the 1490
and 1550 nm channels. The manufactured device showed the 1-dB bandwidth of 110 nm for the 1310 nm channel. For
the 1490 nm and 1550 nm channels, the 1-dB bandwidth was measured to be 30 nm. The adjacent channel isolation
between the 1490 nm and 1550 nm channels was better than 32 dB. The optical isolation between the 1310 nm and
1490 and 1550 nm channels was better than 45 dB. Applications of the planar reflective gratings in the FTTH networks are discussed.
While investment in sub-wavelength silicon photonics research has gained popularity, Kotura has forged significant
customer traction with first generation silicon-photonics products by focusing on manufacturable designs and processes.
This paper reviews recent gains in engineering developments where mature monolithic and hybrid methods are
integrated to form high-performance manufacturable products with proven long-term reliability. Components and
methods are described that lead to photonic modules and subsystems suitable for automated manufacturing techniques.