Robert Atkins

Latent Electro-Static Damage in Vertical Cavity Surface Emitting Semiconductor Laser Arrays

We describe a novel type of failure mechanism for arrays of vertical cavity surface emitting lasers, such as those used in parallel optical interconnects for clustered computer systems. Conventional failure mechanisms related to electrostatic discharge (ESD) during laser manufacturing will cause multiple lasers in an array to fail at once, shortly after the ESD event. We have found that in some cases, latent ESD damage can occur; the ESD site serves as a nucleation point for dark line defects, which migrate under applied voltage. In this manner, individual elements in the laser array can fail randomly, without affecting adjacent lasers in the same array; furthermore, these failures can occur after 30-40 days of continuous operation. We report empirical data on the failure analysis used to identify this effect, including images of the latent damaged lasers, and recommend procedures for avoiding this damage during manufacturing.

Security feature comparison for fibre channel storage area networks switches

This paper presents the results of an independent comparison of security and intrusion detection features implemented in fibre channel fabric switches. These switches are a key element in optical storage area networks. Using an enterprise testbed with mainframe servers and multiterabyte storage, we evaluate four major switch platforms and compare the results. We also consider security concerns for optical channel extension into the metropolitan area network (MAN) using wavelength division multiplexing.

Fiber-Optic Transceivers

Publisher Summary Over the years, discrete solutions in most of the datacom applications are replaced by fiber optic transceivers (TRX). Each TRX is a combination of a transmitter (Tx) and a receiver (Rx) in a single common housing. The transmitter unit, with either a light-emitting diode (LED) or an edge or vertical-emitting laser diode (LD) as its radiation source, and the receiver unit, which in most cases is a positive-intrinsic-negative (PIN) photodiode, are connected together to the transmission medium, either multimode or single-mode fiber. Thus, transceivers characteristically have duplex optical receptacles at one side of the housing, which fit to the corresponding duplex connectors contrary to typical telecom applications with single-fiber optic connectors. The implementation of more or less electronics with integrated circuits and passive components into the Tx and Rx units depends on the application. This chapter discusses the aspects of operation and the application of fiber optic transceivers in the physical layer (PHY), along with some innovative tendencies for the integration of more data transport functions into these components or for a significant reduction of size and power consumption.