Brian Andrew Schuelke

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.