Monolithic multistage optical switch operating at 160 Gb/s line rate

A four input, four output multi-stage optoelectronic switching circuit is implemented on an active-passive regrown InGaAsP/InP epitaxial wafer. The circuit incorporates shallow low-loss waveguides and waveguide crossings in combination with deeply-etched low-radius (0.1 mm) waveguide bends and multimode interference couplers to enable very high density circuit design. Each stage in the circuit comprises a two-input, two-output crossbar switch implemented with semiconductor optical amplifier gates. These are configured for an N-stage planar network devised with four inputs and four outputs. Data integrity is analysed with 160 Gb/s optically time multiplexed data. Power penalties are derived from bit error rate measurements to give values of 0.6 and 1.2 dB over two and four stages of crossbar switches, respectively. The feasibility of such high serial line rates within highly sophisticated optoelectronic integrated circuits is increasingly important to exploit bandwidth agnostic energy consumption in such optoelectronic switching circuits. Energy consumption from the semiconductor optical amplifier gates is estimated at only 3 pJ/bit for the fully loaded circuit operating at 160 Gb/s for each of the four input paths.