Tunable dispersion compensating grating in a 10Gbit/s 100-220km step index fibre link

Chirped fibre gratings are of particular interest for compensating the dispersion (~17ps/nm.km @ 1.55µm) of installed step index (SI) fibre links since they are compact, low-loss, polarisation-insensitive and offer high negative-dispersion. In this paper we present a detailed investigation of the bandwidth-dispersion trade-off for a fixed (40mm) length tunable linearly-chirped fibre grating. In addition we demonstrate that such a grating can precisely compensate the dispersion in a 10Gbit/s transmission experiment for SI fibre lengths in the range 103-216km

Optimal pumping of erbium-doped-fibre optical amplifiers

By choosing pump wavelengths which avoid excited-state absorption, efficient, high-gain, erbium-doped fibre amplifiers are possible. Practical pump wavelengths of 532nm and 980nm are identified as optimal, the latter giving a gain as high as 2.2dB/mW of pump

Dispersion compensating chirped fibre gratings

The dispersion characteristics of linearly chirped fibre gratings have been studied in detail and design criteria established. It is shown that in order to compensate the linear dispersion of 100km of standard fibre, over a certain FWM bandwidth, the required fibre-grating length is 17.7cm/nm. Dispersion Compensation measurements for both a 200km, 2.5Gbit/s direct-modulated transmitter and a 216km, 10Gbit/s externally-modulated transmitter experiment confirm these predictions

A dispersion tunable grating in a 10 Gb/s 100-220km step index fibre link

A dispersion tunable 40mm fiber grating has been employed in a 10Gb/s, stepindex fiber link. Dispersion is effectively compensated for span lengths in the range 103-217km. However, at the longer spans the increased dispersion of the grating results in a reduced bandwidth and therefore its center wavelength is found to be critical (±0.005 nm)

A dispersion tunable grating in a 10Gbit/s 100-220km step index fibre link

A dispersion tunable 40mm fibre grating has been employed in a 10Gbit/s, step-index fibre link. Dispersion is effectively compensated for span lengths in the range 103-216km. However, at the longer spans the increased dispersion of the grating results in a reduced bandwidth and therefore its centre wavelength is found to be critical (± 0.005nm)

Efficient pump wavelengths of the erbium-doped-fibre optical amplifier

By choosing pump wavelengths at which excited state absorption does not occur, efficient high gain operation of erbium-doped fibre amplifiers is possible. Practical pump wavelengths of 532nm and 980nm are identified as optimal, giving gains as high as 1.35 dB/mW and 2.2 dB/mW of pump at the two wavelengths, respectively