Non-linear transmission in germanosilicate fibres at blue/green wavelengths

Many fibre-based devices rely on the ability to transmit light at high intensities down single-mode fibres. Examples are fibre lasers, amplifiers, second-harmonic generators and simple fibre-based high power delivery systems. It is thus important to know whether any non-linear processes exist that could restrict the usefulness of the fibres used in these applications. Brown et al (1984) have reported that non-linear effects of this kind do indeed occur at Argon ion wavelengths in germanosilicate fibre, limiting the power that can be delivered to some tenths of a W over only few-metre lengths of single-mode fibre. The authors report the chief results of an extensive investigation into this effect in germanosilicate HiBi fibres designed to transmit single-mode blue/green light