Abstract

The passive generation of femtosecond pulses in erbium-doped fibre lasers has recently become of considerable interest. The Figure-8 laser configuration whose operation is based on the reflection properties of the Nonlinear Amplifying Loop Mirror has been the object of considerable study [1,2]. It has been shown that the Figure-8 laser can operate in at least two distinctly different modes: in a 'soliton' regime producing relatively chirp-free, transform-limited, sub-picosecond pulses and in a 'square' pulse regime characterised by long (≈150ps) pulses, having a broad optical bandwidth (>35 nm)[3].

© 1992 The Author(s)