Ultrashort pulse lasers based on fiber optic architecture will play a dominant role in the spread of these lasers into research and industrial applications. The principle challenge is to generate adequate pulse energy from singlemode or quasi-singlemode amplifiers which have small cross-sectional area. We demonstrate a robust, all-fiber erbium amplifier system that produces >100 μJ per pulse with 701 fs pulsewidth and M<sup>2</sup> < 1.3. We will discuss the salient amplifier dynamics that influence the pulse generation, shaping, and propagation phenomena in state-of-the-art erbium fiber lasers. Furthermore, we show data relevant to applications and implementation of ultrashort pulse lasers.