30 January 2018
POET demos functionality of PIN photodetector targeting 100-400G optical transceivers
© Semiconductor Today Magazine / Juno PublishiPicture: Disco’s DAL7440 KABRA laser saw.
POET Technologies Inc of Toronto, Canada and San Jose, CA, USA — a designer and manufacturer of optoelectronic devices, including light sources, passive waveguides and photonic integrated circuits (PIC) for the sensing and datacom markets — has demonstrated a high-frequency waveguide-integrated PIN photodiode targeting 100G and 400G data-center applications.
The firm’s PIN photodetector has demonstrated a 3dB optical bandwidth of 37GHz, which is a typical requirement for achieving 50GBaud data rates. The achieved native bandwidths are more than capable of supporting the requirements of 100G receive optical engines (4 lanes at 25Gb/s each) and they can be extended to support 200G/400G engines. Unlike more conventional top-entry PIN photodiodes, POET utilizes an evanescently coupled twin-waveguide structure with integrated spot-size converters that is compatible with the firm’s new Optical Interposer Platform and is designed to operate at wavelengths of 1310-1550nm.
The waveguide-integrated PIN diode is said to provide good responsivity with superior flatness of the RF response. Additionally, the integrated spot-size converter increases fiber-coupling efficiency as well as alignment tolerance. This key differentiating feature of the technology and product enables the PIN detectors to be passively placed on the receive side of an optical interposer without compromising coupling efficiency, says POET. This approach is expected to result in lower production costs during volume manufacturing.
The firm has been able to demonstrate fiber-coupled responsivity in excess of 50%, meeting the initial requirements for a receive optical engine. The integrated waveguides are also engineered to exhibit low polarization-dependent loss (PDL) – a key requirement for PIN photodiodes.
POET is working to provide engineering samples for its PIN photodetectors by mid-2018 for use in its receive optical engines. Engineering samples of its receive optical engines will utilize the new Optical Interposer Platform.