Linearization of an Analog Fiber-Optic System Using the Quasi-Feedforward Technique

摘要

This report discusses the use of the quasi feedforward linearization technique for improving the range over which an analog fiber optic system can provide distortion less performance when the optical source is an incoherent device such as an LED. Coherent sources such as a laser are usually dominated by nonlinear effects, such as modal interaction in the fiber and reflections of light from the fiber back into the laser cavity, that cannot be eliminated by external compensation. The technique of quasi feedforward linearization focuses upon deriving a predistorted signal from one optical source that causes distortion cancellation when used to drive a second optical source with similar nonlinear characteristics. The predistorted signal is derived by using two feedforward summations.