Design of gain-clamped doped-fiber amplifiers for optimal dynamic performance

Abstract

Abstract-This paper provides a detailed analysis of gainclamped doped-fiber amplifiers and design guidelines in a wavelength division multiplexed (WDM) networking environment. A simple dynamic model of the doped-fiber amplifier allows us to derive explicit expressions for the small-signal response, which help identify and optimize the most critical parameters for best dynamic performance. The most important parameter is the pump power, which should be chosen 1-2 dB's above its required open-loop value, with all channels present, for the required signal gain. In an all-optical networking scenario with input power per channel as high as 03 dBm the required pump power may well exceed 20 dBm. Thus optimization of other parameters such as laser wavelength and loop loss are important. For best dynamic performance either the loop loss should be extremely small, implying a very large laser flux, or the laser gain variation in response to a perturbation should be large. Accordingly, the laser wavelength should be placed either close to the unity-gain region of the clamped gain profile, or at its peak. Finally, the small signal model for a chain of clamped amplifiers is provided, and it is shown that long chains are vulnerable to low-frequency input signal perturbations.Index Terms-Doped-amplifier gain dynamics, erbium-doped fiber amplifier (EDFA), gain-clamping.

Restraining effect of film thickness on the behaviour of amplified spontaneous emission from methylammonium lead iodide perovskite

“…8, which shows the plot of ΔE versus n 1/3 for the 650 nm particular sample. Due to the 3D and cavity-free structure of the present sample and the relatively big laser spot size of ∼2 mm, different scattering and other gain losses can likely result in a gain clamping condition [35]. As a result of gain clamping, the carrier density does not increase significantly when increasing the fluence.…”

Transient analysis of short, high-concentration, gain-clamped Er/sup 3+/-Yb/sup 3+/ codoped fiber amplifiers

“…Here, we also note the similarity between the dynamic behavior of nonclustered gain-clamped EYDFA and the low-concentration gain-clamped EDFA [15]- [18]. The amplification process of the signal saturates the homogeneous Er 3+ inverted population below the threshold value, and the recovery time of the signal power undershoot depends on the pump efficiency [17]. Increasing the number of clustered Er 3+ ions also increases absorption losses.…”

EDFA gain stabilization with fast transient behavior by use of a semiconductor optical amplifier

“…Its evolution is inherently slow because of excited state low feeling rates. Additionally, as soon as the gain is able to compensate the global ring a2918_1.pdf JTuA84.pdf ©OSA 1-55752-834-9 losses, the EDFRL emission power starts to oscillate (fig 2b, t = 0.35ms) with relaxation oscillations exhibiting the slowest frequency and the largest power excursions that can be considered [3] (compare with drop sequence). Finally and as can be noticed from fig 2b/2c, steady-state is not even completely reached after 0.55 ms.…”