All-Optical Low-Power 2 $\,\times\,$2 Cross/Bar Switch With a Single Semiconductor Optical Amplifier

An all-optical 2 × 2 cross/bar switch is demonstrated exploiting nonlinear polarization rotation in a single semiconductor optical amplifier. The proposed architecture allows operation with packets at the same input wavelengths and does not require high-speed clock control pump signals. Bit-error-rate measurements at the switch output ports for both cross/bar configurations and for both cases of one and two packet signals connected to the input ports are performed. A maximum of 2.3 dB of power penalty was observed in the worst case. The switching energy was as low as about 400 fJ per bit at 10 Gb/s.