An accurate technique was implemented to measure spectral hole burning in rare-earth amplifiers at room temperature, showing that thulium-doped fiber amplifiers exhibit hole depths four times lower than those of C -band erbium-doped fiber amplifiers.

It is shown that, used in conjunction with 1550-nm pumping, 1047-nm pumping is more suitable to operate the TDFA in the short wavelength band while 1400-nm pumping is more efficient for the long wavelength band.

A new pumping scheme (1.2 /spl mu/m+1.4 /spl mu/m) is demonstrated for the gain-shifted TDFA, leading to record efficiency of 48% using one single pump dual-wavelength laser. This pumping scheme was implemented with a dual wavelength Raman fiber laser, giving 48% optical efficiency.

We present a spectroscopic background in order to optimize Tm doped S-band Optical fluoride fiber amplifiers.We measure the excited state absorption spectra between 1 and 1.5 μm and discussed the choice of amplifier pump wavelengths.

With 1064 nm pumping, 5 dB extra gain is exhibited, and with a two-wavelengths pumping, 5 nm gain broadening and 16 nm gain shifting are experimentally shown for the thulium doped fluoride fiber amplifier.

A lumped optical fibre amplifier exploiting the full spectrum of optical fibres and delivering a record bandwidth of 17.7 THz (between /spl lambda/=1297 nm and /spl lambda/=1605 nm) has been achieved using a combination of erbium-doped, thulium-doped and Raman fibres.

We experimentally and numerically assess the performance of an optical PMD compensator based on the degree of polarization measurement. Assuming a maximum 3 dB power penalty and 10(-3)% outage probability, we show that the maximum tolerable PMD value can be extended from 16 to 33% of the bit duration without and with compensation, respectively. (C) 2000 John Wiley & Sons, Inc.