A*STAR, Fujikura demo 40-60Gb/s silicon optical modulators

Fujikura Ltd has teamed up with Singapore's A*STAR Institute of Microelectronics (IME) to unleash what they say is the world's first 40-60Gb/s silicon-based optical modulators. According to them, the device features advanced multi-level modulation formats for high speed long-haul data transmission. It also represents a move towards low cost, ultra-high bandwidth and small footprint optical communications on silicon platform, they added.

The adoption of multi-level modulations, in a simple quadrature phase-shift keying (QPSK) and differential-QPSK (DQPSK) format, significantly increases the information capacity and thus total data communication throughput for a given optical channel.

Comprising a set of silicon phase-shifters that are integrated in a nested Mach-Zehnder configuration, the modulator has demonstrated high communication speeds of more than 40Gb/s and more than 60Gb/s for DQPSK and QPSK, respectively. For instance, for a channel grid spacing of 50GHz, 40G DQPSK results in a spectral efficiency that is twice that of 20G with conventional on-off keying (OOK) format that is widely used commercially at present. Compared to conventional lithium niobate modulators, the modulator is much smaller in footprint and is significantly cheaper to fabricate as it is CMOS-compatible.

The development in the silicon optical modulator by IME and Fujikura demonstrates that reaching ultra-high performance levels on silicon platform technology is now a reality, thus providing a huge impetus towards driving future ultra-high bandwidth optical communications, the companies stated.