Analytical formula for the transient response of erbium-doped fiber amplifiers.

In wavelength-division-multiplexing systems with optical amplifiers, channel drop or add can cause power changes in the existing channels. We present an analytical formula for the transient power of the existing channels as a function of time when one or more input channel is dropped or added on an erbium-doped fiber amplifier (EDFA). Although this formula was originally derived from perturbation theory of single-stage EDFA's, it is a good approximation of large-power excursion cases as well as two-stage EDFA's.

Linewidth-narrowing mechanism in lasers by nonlinear wave mixing.

We propose a linewidth-narrowing mechanism in lasers by nonlinear absorptive wave mixing of the counterpropagating beams in the cavity. We give a theoretical analysis and report on a demonstration of the effect with an erbium-doped fiber laser. The system also exhibits bistability in the dependence of the oscillation intensity versus pump power.

Uniform performance of high-efficiency room-temperature GaInAsSb/GaSb photodiodes for 1.75 < lambda < 2.2 mum.

A group of 126 experimental, packaged, backilluminated, 1.75-2.2-microm wavelength, GaInAsSb mesa (~85-microm diameter) photodetectors have been assembled and evaluated. Average room-temperature properties were peak quantum efficiency, 86%; zero-bias capacitance, 3.9 pF; dark current at -0.5-V bias, 7.4 microA.

Efficient erbium-doped fiber amplifier at a 1.53-microm wavelength with a high output saturation power.

An efficient erbium-doped fiber amplifier providing gains from +25 to +37 dB with pump powers at lambda = 1.49 microm in the 11-54-mW range is described. Corresponding saturation output powers of +2.5 to +11 dBm were achieved. A maximum gain coefficient of 2.1 +/- 0.1 dB/mW was measured, which is to our knowledge the highest value reported for erbium-doped fiber amplifiers pumped near lambda = 1.49 microm and matches previously reported results for a lambda = 980-nm pump.