Hybrid MZI-SOA InGaAs/InP Photonic Integrated Switches

A low-power, high-performance integrated 4 × 4 hybrid Mach-Zehnder interferometer (MZI) semiconductor optical amplifier (SOA) optical switch is designed, fabricated, and characterized. The 4 mm × 6 mm device is fabricated using an active-passive integration scheme in an InGaAsP/InP foundry. MZIs are implemented as the main switching elements and short switchable SOAs are used to either compensate the loss or suppress the crosstalk. A dilated Beneš architecture is implemented to reduce the crosstalk and offer rearrangeably nonblocking connections. The 4 × 4 switch exhibits a low 1.3-dB loss, a crosstalk ratio of -47 dB, and more than 13-dB input power dynamic range (IPDR) for a 0.5-dB power penalty at a 10-Gb/s signal rate. By active control of injection currents into the SOAs, a fixed output power is achieved for a 10-dB range of input power and the IPDR is extended by at least 4 dB. A 12-mA control current tolerance has been demonstrated for a 10-dB IPDR. The performance of a 16 × 16 switch is emulated by cascading two 4 × 4 chips. A record IPDR of 15 dB at a 1-dB penalty is achieved with a 0.6-dB power penalty floor.