%0 Journal Article
%T Progress on High-Speed 980£¿nm VCSELs for Short-Reach Optical Interconnects
%A Alex Mutig
%A Dieter Bimberg
%J Advances in Optical Technologies
%D 2011
%I Hindawi Publishing Corporation
%R 10.1155/2011/290508
%X Progress of high-speed vertical cavity surface emitting lasers (VCSEL) operating around 980£¿nm is reviewed. A special focus is on their applications for future short-reach optical interconnects, for example, in high-performance computers (HPC). The wavelength of 980£¿nm has fundamental advantages for these applications and plays a significant role in VCSEL research today. The present data rates of 980£¿nm VCSELs exceed 40£¿Gbit/s, and excellent temperature stability has been reported. The major concepts leading to these impressive developments are presented. 1. Introduction The perpetually increasing demand of our modern society for ever faster access to ever larger amounts of information requires a corresponding permanent increase of the computational power of data centres and high-performance computers (HPC) for rapid and efficient data processing and routing. The motor of the progress in HPC performance is the downscaling of Si-based integrated circuit (IC) technology, as predicted by Moore¡¯s Law. While currently the fabrication process of complementary metal-oxide-semiconductor (CMOS) ICs is based on the 32£¿nm technology node, future generations of CMOS chips based on 22, 15, 11, and 8£¿nm technology nodes are expected to appear just within a decade from now [1]. The ever increasing computational power of central processing units (CPU) and storage capability of memory elements logically and unavoidable requires a corresponding strong increase of the performance of data transmission lines connecting chips with each other. Traditional copper-based interconnects quickly run into their physical limitations as signal frequencies approach 10£¿GHz, which are among other high losses, large signal attenuation, large power dissipation, signal distortion, electromagnetic interference (EMI), and crosstalk [2¨C6]. The ultimate solution is brought by optical interconnects [7¨C11], which are consistently replacing wire-based electrical links for rack-to-rack, box-to-box, and board-to-board communication and penetrating to even shorter transmission distances. It is expected that just within a decade from now optical links will reach module and chip levels [7]. The success of the optical technologies in the HPC applications originates from the decisive advantages of vertical cavity surface emitting lasers (VCSEL) [12¨C15] as a high-quality laser light source for short-reach optical interconnects with a large number of channels. The most important and beneficial VCSEL properties are: low-threshold and operating currents; high-efficiency and low-power consumption; a
%U http://www.hindawi.com/journals/aot/2011/290508/