Bidirectional EDFAs That Support E2-Class Power Budget of TWDM-PON Without Using Gain-Clamped Light Source

This paper introduces an Erbium-doped fiber amplifier (EDFA)-based solution to support the maximum link budget class (E2) of the time- and wavelength-division multiplexed passive optical network (TWDM-PON). Bidirectional EDFAs, each consisting of an L-band EDFA as the downstream WDM signal booster and a C-band EDFA as the upstream WDM signal preamplifier, are utilized to reduce the number of EDFAs required. Technical challenges are how to widen the input dynamic range of upstream burst signal detection using a preamplifier, and how to reduce the number of optical components. To resolve these issues, a novel device configuration is proposed, where a very short C-band EDF is pumped by a high-power pump light and the pump power unused by the C-band EDF is reused to pump the L-band EDF. A prototype integrated in an MSA-size package is developed, and its effectiveness in supporting the E2-class power budget is experimentally confirmed.