Two-photon absorption pumping (TPA-induced pumping) is responsible for significant and rapid gain and phase shifts within the semiconductor optical amplifier (CRSOA) carrier reservoir.

Recent research by Amer Kotb and Li Wei, both from the Changchun Institute of Optics, Fine Mechanics and Physics of the Chinese Academy of Sciences, and Kyriakos Zoiros, from the Democritus Universität of Thrace, Greece, has combined the physical benefits of TPA and those of CR-SOAs in order to theoretically implement all-optical XOR, OR, OR NAND and XNOR logic gates at a data speed of 320 Gb/s

The study was published in Optik. The performance of the logic gates studied was not previously investigated using CR-SOAs at 320 Gb/s.

The Mach-Zehnder Interferometer has two symmetrical CR–SOAs arranged in each of its two arms. The OR logic gate is constructed by combining a CR–SOA and a delayed interferometer. The quality factor (QF), and the associated bit error rate (BER) were used to evaluate the performance of the gates.

Researchers also compared their work with the published schemes for theoretically implementing logic gates using (CR)-SOAs at various speeds.

Simulation results showed that these logic gates could be implemented at 320Gb/s with much better QF, BER, and TPA when TPA is included in CR-SOAs. However, this is impossible without TPA since the metrics are severely degraded.