ABSTRACT
Transparency of a 91-km distributed erbium-doped fiber is achieved with 0.46 mW/km of pump power at a signal power of -12 d Bm. The accumulation of amplif ier noise is measured to be smaller than the minimum noise accumulation that can be achieved in a 91-km link with two lumped amplifiers separated by 45 km.
ABSTRACT
A measurement technique is described in which the radiative quantum efficiency of certain transitions in rare-earth-doped glasses can be determined based only on relative fluorescence measurements. We calibrate the emission from the level of interest by measuring emission into that level from a higher excited level. Application of the technique to Pr(3+)-doped sulfide glasses yields quantum efficiencies for the (1)G(4) ? (3)H(5) transition as high as 60%, in good agreement with measurements using the integrating sphere technique. Calculated efficiency values based on the Judd-Ofelt technique are shown to be subject to inherent uncertainties.
ABSTRACT
A single-mode lead silicate optical fiber has been fabricated to permit lower-power all-optical switching. The core glass has a nonlinear index of refraction eight times that of silica. The loss of the fiber is less than 2 dB/m. Over 177pi of phase shift was obtained, as measured by self-phase modulation, in a 29-cm length of fiber. At the 1-kW peak power level required to produce this large phase shift, two-photon absorption and stimulated Raman scattering did not significantly degrade the desired nonlinear behavior.
ABSTRACT
The effect of an axial index depression on GRIN lens performance is studied analytically. Significant image deterioration can occur depending on the perturbation magnitude.
