Multiple wavelength Er-doped twincore fibre loop laser

Multiwavelength laser operation of an inhomogeneously broadened Er-doped twincore fibre loop laser is demonstrated. Equal output power, separation 0.5nm and linewidth <10kHz was confirmed for each mode in a 3 wavelength laser. Up to 8 wavelength operation has been observed, demonstrating that twincore EDFAs can provide channel equalisation in an 8-channel multi-amplifier optical network

Triple-frequency operation of an Er-doped twincore fibre loop laser

Simultaneous laser operation of three single-frequency modes from an inhomogeneously broadened Er-doped twincore fiber loop laser is reported. Equal output power of 390µW separation 0.5 nm and linewidth <10 kHz was measured for each mode in a travelling wave cavity comprising a single gain medium. In addition up to eight wavelength operation has been observed, demonstrating that twincore EDFAs can provide channel equalization in an eight-channel multiamplifier optical network

Passive spectral gain control of a 4-channel WDM link employing twincore erbium doped fibre amplifiers

A channel power equalising WDM link using twincore erbium doped fibre amplifiers showing inhomogeneous properties has been investigated. Non-divergent and self regulating propagation of a 4 wavelength channel systems is demonstrated employing twincore EDFAs

Erbium-doped-fibre optical limiting amplifiers

A novel configuration of an erbium-doped-fiber optical output-limiting amplifier (OLA) is presented which is realized by simply introducing a differential lump-loss between the signal and the pump power at a particular point along the fiber. The OLA exhibits an input-power dynamic range in excess of 40 dB and the capacity to control optically the level of the constant-output signal

Self regulating spectral characteristics of a 4 channel WDM link utilizing twincore erbium doped fibre amplifiers

A channel power equalising WDM link using twincore EDFAs has been investigated. Non-divergent and self regulating propagation of 4 wavelength channels is demonstrated in a 910 km link employing 14 twincore EDFAs. The inhomogeneous properties of the gain of this new amplifier type are analysed

Channel power equalising WDM link incorporating twincore erbium doped fibre amplifiers

The power spread of two WDM channels in a 975km link employing 15 EDFAs has been reduced from ~14dB to ~2dB using twincore erbium doped fibre amplifiers with a channel equalisation of ~1dB per stage

Brachiaria spp. poisoning of ruminants in Brazil

Brachiaria species are the most important grasses for cattle production in Brazil. However, a limiting factor for the use of Brachiaria spp. is their toxicity. Most outbreaks of hepatogenous photosensitization are caused by B. decumbens; however B. brizantha, B. humidicola and B. ruziziensis can also cause poisoning. The poisoning affects cattle, sheep, goats and buffalo. Sheep are more susceptible than other animal species and the young are more susceptible than adults. There are differences in susceptibility among animals of the same species and it has been suggested that this resistance is genetic. Also has been suggested that buffalo and probably some sheep are resilient, i.e. when poisoned these animals have histologic lesions and high GGT serum concentrations, but do not show clinical signs. In general, saponin concentrations are higher in growing plants, but outbreaks occur all over the year, probably due to unexplained rise in saponin concentration in the plant. A clinical syndrome of progressive weight loss and death, without photosensitization, has been reported in cattle poisoned by B. decumbens. Main preventive measures are based on the selection of resistant or resilient animals and on the development of Brachiaria species or varieties with low saponin concentration