March 22, 2010 -- CyOptics Inc., designer and manufacturer of photonic integration circuits (PICs), announced the demonstration of a 0.5 Tbps (500 Gbps) transmit optical subassembly (TOSA) and receive optical subassembly (ROSA) targeted at next-generation Ethernet applications.
The PIC components leverage a combination of monolithic and hybrid integration to deliver 500 Gbps in a single pair TOSA/ROSA pair.
While the IEEE is expected to ratify a standard for 100G Ethernet by the middle of 2010, initial industry and standard body discussions have already started on how to make the next leap to 1 terabit to meet the ever-increasing demand for optical bandwidth. The 500G demonstration marks the completion of the second-year milestone as part of a three-year project funded by the U.S. Commerce Department’s National Institute of Standards and Technology (NIST) Advanced Technology Program (ATP) to develop the next-generation Terabit Photonic Integrated Circuit (TERAPIC). The final project goal targets the demonstration of optical laser and receiver components for transmission speeds of up to 1 Tbps (1,000 Gbps) by the end of 2010.
The TOSA encompasses 12 electro-absorptive modulated lasers (EMLs) with wavelength channels from 1270 to 1380 nm on a 10nm channel grid. The lasers are grouped in three arrays with each array monolithically integrating four EMLs. Each EML has a typical small-signal bandwidth of >30 GHz allowing non-return-to-zero (NRZ) operation at 43 Gbps. The three EML arrays are flip-chip bonded to a planar lightguide circuit (PLC), which serves as the mounting platform and provides the optical multiplexer (MUX) function.
The ROSA couples the signal through an optical PLC-based de-multiplexer to 12 high-speed PIN detectors with a 3-dB bandwidth of more than 50 GHz and a continuous wave (CW) responsivity of 0.8 A/W.
The PLCs for this demonstration used Silicon on Insulator (SOI) technology designed and fabricated by Kotura, CyOptics’ partner in the ATP/NIST project. For the future commercialization of the TERAPIC technology, CyOptics intends to also leverage its in-house Silica PLC platform.
The transmission tests were performed over 2 km of SMF with each channel tested at 40Gbps. For the demo, a commercial SOA was used in front of the ROSA to boost the signal. Each channel was tested to be error free to <10-11 BER with most <10-12 BER. The total cross-talk was measured to be between 1 and 2 dB. The channel spacing of 10nm was chosen to enable the TOSA operation without using a Thermo-Electric-Cooler (TEC) in order to reduce the overall power dissipation. Instead of a TEC, resistive heating can be used to limit the temperature excursions and to enable an operating range of the TOSA from -5 to +75 degC.