Optical fiber communication systems: Optical amplifiers and potential exposure to radiant energy

The evolution of optical fiber communication systems (OFCS) has seen a dramatic increase in the optical power within systems. Contemporary systems utilizing high-power optical amplifiers (OA) can operate at power levels well above one watt. While during intended use an OFCS is completely enclosed and radiant energy is inaccessible, however, during system development, deployment, maintenance and service, there is a potential risk for exposure. Typically, OA operate in the infrared “B” region of the electromagnetic spectrum (>1.4 um), where virtually all of the energy is absorbed by surface tissue of the body (i.e., the cornea of the eye, the epidermal layer of the skin). Beam divergence associated with laser diodes and optical fibers also plays an important role in hazard assessment. This paper describes the relationship between these factors (i.e. wavelength, beam characteristics, and power) as they relate to OFCS hazard assessment. Also discussed is the use of optical viewing aids, automatic power reduction systems and laser product classification schemes.