Ronald Lee Soderstrom

CD laser optical data links for workstations and midrange computers

The Optical Link Card (OLC) is a high speed fiber optic data link developed for low cost computer interconnect applications. Several versions of this OLC family are now in volume production. They incorporate a short-wavelength, CD-type laser source, high-density surface mount (SMT) packaging, and a novel technique to comply with worldwide laser safety regulations. The current cards, operating at 220 Mb/s and 266 Mb/s over 2 km of multimode optical fiber, provide compatibility with the emerging ANSI standard called Fiber Channel. Future extensions, especially to higher data rates, are being developed to meet the computer users growing demand for higher bandwidth networking solutions.<<ETX>>

Optical data link using a CD laser

A 266 Mb/s optical link card based on a 780 nm compact disc (CD) laser has been designed by IBM Rochester to provide a fast data link for interconnecting computer systems. This design not only met the performance and cost objectives of the data communications environment, it also overcame key challenges in the areas of laser safety, laser reliability, and modal noise. The 266 Mb/s data rate was selected to conform to the new American National Standard Institute (ANSI) Fiber Channel Standard (FCS).

CD Laser As A Fiber Optic Source For Computer Data Links

Computer data links are evolving from copper cable systems to fiber optics simply because the optical fiber itself offers the advantages of higher data rates and longer distances. The Compact Disc (CD) laser is suitable as the light source because it satisfies the computer system requirements for low cost, high data rate, miniaturized package, and high reliability.

Open fiber control: a laser safety interlock technique

Laser safety has become an important issue in the design of optical data links for computers because semiconductor laser diodes, rather than LEDs, are increasingly being selected as the light source. It is very important that optical data links in the computer environment meet the requirements of a Class 1 laser product (Class 1 is the safest, least restrictive laser safety category) due to the potential for user exposure to laser radiation. This paper presents an overview of an open fiber link detection and laser control system for point-to-point data links referred to as the open fiber control (OFC) system. The system functions by detecting whenever the optical link between two transceiver ports is opened (i.e., an open connector or cut fiber) and forcing the transmitters into a low duty cycle mode of operation that maintains a Class 1 output level from the open link.

Laser Safety Overview For Optical Fiber Data Links

Current design and development activities within the computer industiy are beginning to use semiconductor laser diodes as the light source for optical fiber data links. This trend is occurring because laser diodes have many advantages over LEDs as the preferred light source for both multimode and single mode fiber. As a result, laser safety has become an important issue in the design activity of fiber data link products, both because of the need to produce safe products for the marketplace and because laser safety regulations are enforced in most countries. This paper presents an overview of some of the laser safety issues and regu-lations as they apply to optical data links.