High Speed Vcsels For Optical Interconnects

The transmission speed of data communication systems is forecast to increase exponentially over the next decade. Development of both Si-based high-speed drivers as well as III-V-semiconductor-based high-speed vertical cavity surface emitting lasers (VCSELs) are prerequisites for future ultrahigh data-rate systems. This thesis presents: - a survey of the present state of the art of VCSELs - a systematic investigation of the various effects limiting present VCSELs - a catalogue of solutions to overcome present limits - detailed progress in modelling, fabricating and testing the currently most advanced VCSELs at the two commercially most important wavelengths.

The huge progress which has been achieved in the field is covered here, in the first comprehensive monograph on vertical-cavity surface-emitting lasers (VCSELs) since eight years. Apart from chapters reviewing the research field and the laser fundamentals, there are comprehensive updates on red and blue emitting VCSELs, telecommunication VCSELs, optical transceivers, and parallel-optical links for computer interconnects. Entirely new contributions are made to the fields of vectorial three-dimensional optical modeling, single-mode VCSELs, polarization control, polarization dynamics, very-high-speed design, high-power emission, use of high-contrast gratings, GaInNAsSb long-wavelength VCSELs, optical video links, VCSELs for optical mice and sensing, as well as VCSEL-based laser printing. The book appeals to researchers, optical engineers and graduate students.

As we reach the data transmission limits of copper wire and communications experts seek to bring the speed of long-haul fiber optics networks closer to access points, optical interconnects promise to provide efficient, high-speed data transmission for the next generation of networks and systems. They offer higher bit-rates, virtually no crosstalk, lower demands on power requirements and thermal management, and the possibility of two-dimensional channel arrays for chip-to-chip communication. The Handbook of Optical Interconnects introduces the systems and devices that will bring the speed and quality of optical transmission closer to the circuit board. Contributed by active experts, most from leading technology companies in the US and Japan, this outstanding handbook details various low-cost and small-size configurations, illustrates the discussion with more than 300 figures, and offers a look at the applications and future of this exciting and rapidly growing field. The book includes a detailed introduction to vertical cavity surface-emitting lasers (VCSELs); the use of optical interconnects in metropolitan, local-area, and access networks through FTTP (FTTH); and Jisso technologies, which are critical for developing low-cost, small-size modules. Driving down the size and cost of optical interconnects is vital for integrating these technologies into the network and onto microprocessors, and the Handbook of Optical Interconnects provides the knowledge and tools necessary to accomplish these goals.

Vertical Cavity Surface Emitting Laser (VCSEL)-based data links are attractive due to their low-power dissipation and low-cost manufacturability. This chapter reviews the foundations for this technology, as well as the device and module design challenges of extending the data rate beyond the current level. We begin with a review of data communications from the business perspective, and continue with a brief discussion of the current and future standards. This is followed by a survey of recent advances in VCSELs, including data links operating at 28Gb/s. We review the recent efforts on ultra-fast data links and discuss the advantages of the different approaches. We also examine key design aspects of optical transceiver modules and we focus our discussion on novel applications in high-performance computing using both multi-mode and single-mode fiber optics. We highlight the importance of the device/component-level and system-level modeling and show some modeling examples with comparison to measured data. We conclude with a comparison of the VCSEL-based data links with other competing technologies, including silicon photonics and short-cavity edge emitting lasers.

This dissertation provides the first systematic analysis of the dynamic energy efficiency of vertical-cavity surface-emitting lasers (VCSELs) for optical interconnects, a key technology to address the pressing ecological and economic issues of the exponentially growing energy consumption in data centers. Energy-efficient data communication is one of the most important fields in “Green Photonics” enabling higher bit rates at significantly reduced energy consumption per bit. In this thesis the static and dynamic properties of GaAs-based oxide-confined VCSELs emitting at 850 nm and 980 nm are analyzed and general rules for achieving energy-efficient data transmission using VCSELs at any wavelength are derived. These rules are verified in data transmission experiments leading to record energy-efficient data transmission across a wide range of multimode optical fiber distances and at high temperatures up to 85°C. Important trade-offs between energy efficiency, temperature stability, modulation bandwidth, low current-density operation and other VCSEL properties are revealed and discussed.

Dramatic increases in processing power have rapidly scaled on-chip aggregate bandwidths into the Tb/s range. This necessitates a corresponding increase in the amount of data communicated between chips, so as not to limit overall system performance. To meet the increasing demand for interchip communication bandwidth, researchers are investigating the use of high-speed optical interconnect architectures. Unlike their electrical counterparts, optical interconnects offer high bandwidth and negligible frequency-dependent loss, making possible per-channel data rates of more than 10 Gb/s. High-Speed Photonics Interconnects explores some of the groundbreaking technologies and applications that are based on photonics interconnects. From the Evolution of High-Speed I/O Circuits to the Latest in Photonics Interconnects Packaging and Lasers Featuring contributions by experts from academia and industry, the book brings together in one volume cutting-edge research on various aspects of high-speed photonics interconnects. Contributors delve into a wide range of technologies, from the evolution of high-speed input/output (I/O) circuits to recent trends in photonics interconnects packaging. The book discusses the challenges associated with scaling I/O data rates and current design techniques. It also describes the major high-speed components, channel properties, and performance metrics. The book exposes readers to a myriad of applications enabled by photonics interconnects technology. Learn about Optical Interconnect Technologies Suitable for High-Density Integration with CMOS Chips This richly illustrated work details how optical interchip communication links have the potential to fully leverage increased data rates provided through complementary metal-oxide semiconductor (CMOS) technology scaling at suitable power-efficiency levels. Keeping the mathematics to a minimum, it gives engineers, researchers, graduate students, and entrepreneurs a comprehensive overview of the dynamic landscape of high-speed photonics interconnects.

This book describes fully embedded board level optical interconnect in detail including the fabrication of the thin-film VCSEL array, its characterization, thermal management, the fabrication of optical interconnection layer, and the integration of devices on a flexible waveguide film. All the optical components are buried within electrical PCB layers in a fully embedded board level optical interconnect. Therefore, we can save foot prints on the top real estate of the PCB and relieve packaging difficulty reduced by separating fabrication processes. To realize fully embedded board level optical interconnects, many stumbling blocks need to be addressed such as thin-film transmitter and detector, thermal management, process compatibility, reliability, cost effective fabrication process, and easy integration. The material presented eventually will relieve such concerns and make the integration of optical interconnection highly feasible. The hybrid integration of the optical interconnection layer and electrical layers is ongoing.