Modeling of Dy/sup 3+/-doped GeAsSe glass 1.3-μm optical fiber amplifiers

We present a model for optical amplification at 1.3 μm using Dy/sup 3+/ in fibers made from a low phonon energy glass, based on GeAsSe. This model uses in-band pumping at 1.28 μm, takes into account the spectral distribution of amplified spontaneous emission, and allows for bottlenecking of excited ions into the intermediate states in Dy as well as the excited state absorption (ESA) from those levels. Using data obtained from spectroscopic measurements and Judd-Ofelt calculations, our model shows that very high gain (>30 dB) is possible in short lengths (40-100 cm) of fiber. Given the very high quantum efficiency of the radiative transition in this glass, we show that bottlenecking and ESA should not have a significant impact on device performance. We also predict that devices made from this fiber should have a very high tolerance to the passive loss of the fiber.