Reverse bias voltage controlled burst-mode booster SOA in λ-tunable ONU transmitter for high-split-number TWDM-PON

This paper presents a λ-tunable optical network unit (ONU) burst-mode transmitter (B-Tx) with high output power and low burst-off-level power for high-splitnumber time and wavelength division multiplexing passive optical networks (TWDM-PONs). The proposed ONU B-Tx utilizes a burst-mode booster semiconductor optical amplifier (SOA) with a control technique for reverse bias voltage that creates an optical power absorption effect in the burstoff- level state. This paper introduces the design of the biasvoltage- state control circuit, simulations of control-circuit operation, evaluations of the static optical power-absorption effect, and burst-mode operation performance in the booster SOA operated by reverse bias voltage. High output power of over +7.4 dBm and low burst-off-level power of under −73.4 dBm∕15 GHz are successfully achieved in all upstream channels. Crosstalk penalty measurements confirm a very low penalty of under 0.1 dB, which leads to a 256 splitnumber TWDM-PON.