White Papers & Publications
WHITE PAPERS
Silicon Photonics (from the Journal of Lightwave Technology, December 2006)
ABSTRACT: After dominating the electronics industry for decades, silicon is on the verge of becoming the material of choice for the photonics industry: the traditional stronghold of III–V semiconductors. Stimulated by a series of recent breakthroughs and propelled by increasing investments by governments and the private sector, silicon photonics is now the most active discipline within the field of integrated optics. This paper provides an overview of the state of the art in silicon photonics and outlines challenges that must be overcome before large-scale commercialization can occur. In particular, for realization of integration with CMOS very large scale integration (VLSI), silicon photonics must be compatible with the economics of silicon manufacturing and must operate within thermal constraints of VLSI chips. The impact of silicon photonics will reach beyond optical communication—its traditionally anticipated application. Silicon has excellent linear and nonlinear optical properties in the midwave infrared (IR) spectrum. These properties, along with silicon’s excellent thermal conductivity and optical damage threshold, open up the possibility for a new class of mid-IR photonic devices.
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Fundamentals of Silicon Photonic Devices
ABSTRACT: This paper offers a brief introduction to silicon photonics including the basic optical waveguide, passive optical circuit performance, the addition of doped p- and n- junctions adjacent to the intrinsic silicon waveguide to inject a current across the waveguide, free-carrier dispersion, performance of the variable optical attenuator (VOA), and a monolithic, dual-function splitter-VOA array circuit.Download PAPER (292k)
Tuned Attenuation Efficiency of a Silicon Photonic Variable Optical Attenuator with Supplementary Diodes
ABSTRACT: Supplementary diodes were introduced into a Silicon photonic variable optical attenuator, formed by 4 forward-biased lateral p-i-n diodes connected in series, in order to tune its attenuation efficiency.Download (447k)
Integrated Silicon Photonic Circuit: Monolithic 8-Channel Modulator, Tap, Vertical Coupler, and Flip-Chip Mounted Photodetector Array
ABSTRACT: This paper describes a silicon photonic circuit of eight fiber-optic input ports, each port leads through an electro-photonic modulator to a 0.95/0.05 coupler, where the 95% signal is guided to a fiber-optic output port and the 5% signal is terminated by a vertical coupler and a down-looking photodetector. Applications include telecommunication equipment requiring microsecond speed for rapid power balancing, transient suppression, and subcarrier modulation for channel tracking and system health monitoring. Circuit elements and initial measurements are described.Download (377k)
Monolithically-integrated SOI-based planar lightwave filter for passive optical network applications
ABSTRACT: A monolithically-integrated design and fabrication of a silicon-on-insulator filter is described. The filter uses a combination of a cascaded Mach-Zehnder structure and a planar reflective grating to multiplex 1310 nm channel and demultiplex 1490 and 1550 nm channels for applications in passive optical networks.Download (141k)
Progress in Manufactured Silicon Photonics
ABSTRACT: 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.Download (525k)
PUBLICATIONS
Ultra VOA Array Application Note: Transient Suppression and Channel Identification and Control
ABSTRACT: It is a well-established practice for communications systems designers to use variable optical attenuators (VOAs) for controlling optical power levels in front of receivers, amplifiers and for channel equalization. Over the last several years there has been a variety of electrically actuated opto-mechanical VOAs commercialized for such uses. Many important new applications for VOAs are emerging, especially for metro and access networks. Many of these applications require high speed VOAs, eliminating the slow, electrically actuated opto-mechanical VOAs from consideration. To address these new network requirements, Kotura has introduced a line of very high-speed UltraVOATM Arrays that have no such speed limitations. The UltraVOATM Arrays are in production and are qualified to Telcordia GR-1221, GR-1209, and the applicable portions of GR-468.Download (452k)