Gain stabilization in gain clamped EDFA cascades fed by WDM burst-mode packet traffic

Abstract

Abstract-This paper studies via simulation the stabilizing effect of all-optical gain-clamping (AOGC) in a chain of erbium-doped fiber amplifiers (EDFA) fed by wavelength-division multiplexing (WDM) burst-mode packet traffic. AOGC is necessary to suppress swings of output power and optical signal-to-noise ratio (OSNR). A case study is selected, in which only the first EDFA in a cascade of six amplifiers is clamped using a ring laser configuration. A numerical model which solves the transcendental equation for the average inversion at each EDFA is used for the analysis. The traffic is generated on the eight WDM channels by ON-OFF time-slotted sources, with statistically independent ON and OFF durations, randomly generated by a truncated Pareto distribution with infinite variance. The simulation model includes the generation of amplified spontaneous emission within each amplifier and the propagation of the lasing power generated in the AOGC EDFA through the cascade. It is shown that the sizable power and OSNR swings arising in an unclamped cascade of EDFA's can be effectively suppressed when a lasing signal a few decibels above the aggregate signal power develops in the AOGC EDFA and propagates along the cascade.Index Terms-Modeling, optical communication, optical fiber amplifiers, transient analysis, wavelength-division multiplexing (WDM).

Internet Protocol-Hybrid Opto-Electronic Ring Network (IP-HORNET): A Novel Internet Protocol-Over-Wavelength Division Multiplexing (IP-Over-WDM) Multiple-Access Metropolitan Area Network (MAN)

“…This result is verified thoroughly with simulations in [23] and experimentally in [61,62]. Figure 4.7 shows an example of EDFA gain dynamics obtained in experiments on HORNET.…”

“…Receiving a signal like the one on Wavelength 2 in Figure 4.7 is very difficult because the SNR [63,62] The gain of an EDFA changes when the input power changes. In this experiment, the peak power on Wavelength 1 is 9.5 dB higher than the peak power on Wavelength 2.…”

Investigations on burst length in optical burst switched networks

“…The transient effect in OBS networks results in power variation in different packets, which could potentially cause misrouting and degradation in signal quality at the node and require a high dynamic range for the receiver. Several approaches have been proposed to control EDFA transients, including the use of a continuous-wave (CW) channel to drive the amplifier into saturation or provide constant total power, or using automatic gain control with optical [5] or electronic feedback to control the power into the amplifier. However, these approaches require a high-power laser source [6], have slow response or suffer from relaxation oscillations [5].…”

“…Several approaches have been proposed to control EDFA transients, including the use of a continuous-wave (CW) channel to drive the amplifier into saturation or provide constant total power, or using automatic gain control with optical [5] or electronic feedback to control the power into the amplifier. However, these approaches require a high-power laser source [6], have slow response or suffer from relaxation oscillations [5]. Tran et al [7] studied a simple technique based on envelope detection to significantly control rapid EDFA transients in optical burst switched networks.…”

Multi-level burst power transient suppression using semiconductor optical amplifiers in gigabit access links

“…Under such conditions the intensity of the individual bursts will vary, giving rise to a multi-level power transient. Numerous methods for dealing with power transients including the use of SOAs [4,5], and various forms of amplifier gain clamping methods [6] have been proposed. In this paper we demonstrate how an SOA operating close to the saturation region of the gain curve reduces the receiver sensitivity penalty associated with multi-level burst power transients in 10 Gb/s transmission.…”