22 March 2010


CyOptics demos record 500Gb/s TOSA/ROSA

Indium phosphide-based optical chip and component maker CyOptics Inc of Lehigh Valley, PA, USA, has demonstrated what is claimed to be an industry-first 0.5Terabit/s (500Gb/s) transmit optical subassembly (TOSA) and receive optical subassembly (ROSA) targeted at next-generation Ethernet applications. The photonic integrated circuit (PIC) components leverage a combination of monolithic and hybrid integration to deliver 500Gb/s in a single TOSA/ROSA pair.

While the IEEE is expected to ratify a standard for 100G Ethernet by mid-2010, initial industry and standard-body discussions have already started on how to make the next step to 1 Terabit/s to meet the ever-increasing demand for optical bandwidth, says CyOptics. The 500G demonstration marks the completion of the second year of the three-year program Terabit Photonic Integrated Circuit (TERAPIC), funded by the US Commerce Department's National Institute of Standards and Technology (NIST) Advanced Technology Program (ATP). The final project goal targets the demonstration of optical laser and receiver components for transmission speeds of up to 1Terabit/s (1000Gb/s) by the end of 2010.

The TOSA encompasses 12 electro-absorptive modulated lasers (EMLs) with wavelength channels from 1270nm to 1380nm 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 >30GHz, allowing non-return-to-zero (NRZ) operation at 43Gb/s. 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 (DeMux) to twelve high-speed PIN detectors with a 3dB bandwidth of more than 50GHz and a continuous-wave (CW) responsivity of 0.8A/W. The current package dimensions of the TOSA are 22mm x 22mm, and the ROSA 30mm is wide x 26mm long.

CyOptics leverages its high-speed InP device technology for the fabrication of the 40G EML array and 40G PIN detectors, as well as its highly automated hybridization and planar packaging platforms for the assembly of the TERAPIC components. The PLCs for the demonstration used silicon on insulator (SOI) technology designed and fabricated by silicon photonics component maker Kotura Inc of Monterey Park, CA, USA, CyOptics’ partner in the ATP/NIST project. For future commercialization of the TERAPIC technology, CyOptics intends to also leverage its in-house silica PLC platform.

The transmission tests were performed over 2km of single-mode fiber (SMF) with each channel tested at 40Gb/s. For the demo, a commercial semiconductor optical amplifier (SOA) was used in front of the ROSA to boost the signal. Each channel was tested to be error free to <10-11 BER (bit error rate), with most <10-12 BER. Total cross-talk was measured to be 1–2dB. The channel spacing of 10nm was chosen to enable TOSA operation without using a thermo-electric cooler (TEC) in order to reduce 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 –5ºC to +75ºC.

See related item:

Kotura demos first silicon photonics mux/demux for 0.5Tb/s transmission

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