Fiber illumination and pulse shape

Abstract

In the previous chapter we described pulse spreading by the maximum temporal width possible, t _max — t _min. Now we investigate pulse spreading more closely by examining the shape of the pulse as it propagates, i.e. the distribution of energy within the pulse, or impulse response. We derive the pulse shape at time t due to an impulse of initially zero width, from which we can describe the response of a pulse of arbitrary initial shape by convolution. The analysis includes only bound rays, since they characterize the transmission properties of long fibers.