All-optical gain-clamped EDFA using external saturation signal for burst-mode upstream in TWDM-PONs

Abstract

While the gain-transient suppression of erbium-doped fiber amplifiers (EDFAs) has been widely studied, the large interval between upstream burst-mode signals from optical network units (ONUs) in time- and wavelength-division multiplexing passive optical networks (TWDM-PONs) presents new challenges. A non-gain-clamped EDFA acting as a preamplifier does not have the desired overshoot on the burst-mode signal when there are only a few ONUs in operation in the TWDM-PON. To solve this problem, we propose an all-optical gain-clamped EDFA (OGC-EDFA) that uses a distributed feedback laser diode to generate a saturation signal. An OGC-EDFA based on a ring laser configuration was also tested to compare the overshoot performance; the both OGC-EDFAs showed negligible overshoot performance. Given the negligible overshoot and wide input dynamic range of the OGC-EDFA, the proposed amplifier is thought to be a simple, low-cost solution for TWDM-PON applications.

Gain-clamped erbium-doped fiber amplifier using a Sagnac loop and low-reflectivity fiber Bragg grating

“…Erbium-doped fiber amplifiers (EDFAs) are widely used in optical fiber communication systems because of their excellent characteristics, including high efficiency, low noise, polarization insensitivity, and compatibility with optical fiber lines [1]. However, a conventional EDFA often causes significant gain variation when the input data stream has a long duration with no signal, such as a burst signal [2,3,4,5,6]. The gain variation often makes it difficult to decide the bit value in the receiver.…”

Single‐/Dual‐FBG‐based gain controller of gain‐clamped L‐band erbium‐doped fiber amplifier with high gain and flatness

“…In the past two decades, erbium‐doped fiber amplifier (EDFA) is always one of the most key devices and plays an important role in optical communications, due to its benefits in terms of gain, bandwidth and cost . With the continuous increase of traffic, the operating band of EDFA needs to be extended from conventional‐band (C‐band, 1525–1565 nm) to long‐wavelength‐band (L‐band, 1570–1610 nm).…”