The market for 43Gbit/s system solutions is showing clear signs of growth, driven by the continuing increase of network traffic through applications such as triple-play and the corresponding expansion of the broadband access networks. As a key player serving this market with ultrafast optoelectronic components, u2t decided it is time to prepare for scalable volume production of our products. External consultants with long-term experience in manufacturing from the former Infineon fiber optics division in Berlin were contracted to give additional guidance on optimizing business procedures and production processes. The consultants (C2GO) specialize in providing process know-how for electro-mechanical and optical sub-assemblies and modules.
New production-related responsibilities like production planning and control, process control and process development, test planning and quality assurance as well as logistics were introduced. In parallel the documentation of business processes was brought forward, targeting an ISO9001-2000 quality management system certification early next year.
Driven by the demands of our system customers, we ran a Telcordia GR-468 compliant test program to prove the reliability of our two main OEM products. These are our well-known ultrafast photodetector in its new hermetic package (XPDV2120R) and the balanced photoreceiver (BPRV2123). They cover the two most important applications: high-power photodetection in optically pre-amplified receivers and balanced detection in DPSK receivers.
Beginning in January 2006, several lots of 11 production samples from both products - BPRV2123 and XPDV2120R - were subjected to the complete set of stress tests recommended in the Telcordia GR-468 standard. Their performance was measured before and after each test. The tests, in close cooperation with customers, included temperature cycling, cycling moisture tests, a high-temperature operating life (HTOL) test at 85°C for 2000 h, vibration and shock tests, thermal shock tests and many more. While most of the tests were done internally at u2t, some were performed at external test labs.
The two products tested are representative of parts and technologies used throughout u2t’s entire photodetector and photoreceiver portfolio. This means that our customers are facing shortened qualification cycles for many products, even if their application requires the use of a different version than the two named parts. The detailed qualification reports will be made available on request to selected customers. This certification is an important milestone for the maturing commercial 43Gbit/s communications market.
Building on a sophisticated rf-design and our waveguide integrated photodiode technology, u2t is now offering photodetectors with an electrical 3dB bandwidth of 70GHz (XPDV3120R). As with our well-established 50GHz photodetectors, the responsivity and polarization dependence can be kept at the usual high performance of typically 0.6A/W and 0.3dB, respectively. The diodes come with a female V™-connector and are well suited for 100Gbit/s NRZ or 80Gbit/s RZ operation.
The picture shows an eye pattern of a 100Gbit/s RZ-ASK modulated signal, generated by 8 x 12.5Gbit/s Optical Time Domain Multiplexing. An average power of +12dBm was detected by the u2t XPDV3120R photodetector and displayed by an Agilent Digital Communications Analyzer equipped with a 70GHz sampling head and precision timebase. (Data provided by courtesy of C. Schubert, Fraunhofer Institute for Telecommunications, Heinrich-Hertz-Institut.)
Recent additions to our photoreceiver product family are the DPRV photoreceivers with differential output using two GPPO connectors. Following the scheme of offering one receiver with high bandwidth (the DPRV2021) and one with high gain (the DPRV2022) they comprise two GPPO sparkplug connectors for convenient and cost effective assembly in a 43 Gbit/s transceiver or linecard application. Both receivers are optionally available with an integrated dc block, allowing compliance with CDR/DEMUX circuits from different technologies using ac coupling.
A high sensitivity of -11dBm in single-ended operation (back-to-back) was measured and about 1dB of improvement is expected when both outputs are used.
u2t and ITF Labs of Canada, a leading producer of all-fibre photonic components, have teamed up to demonstrate a plug-and-play 43Gbit/s receiver for the upcoming demand for phase-modulated optical communication systems. In a joint effort they recently demonstrated the compatibility and superior performance of a combination of their latest product releases for 43Gbit/s differential phase key shifting (DPSK) applications. In this new demonstration an easy to use receiver board consisting of the ITF (DPSK4301Sxx) demux and the u2t (BPDV2120R) balanced detector was assembled. It consists of a new smaller form factor demux, incorporating a temperature sensor and a thin film fibre heater to fine tune the phase of the interferometer and, on the detector side, an integrated high performance balanced detector with improved control over the optical path length, achieving a maximum skew of only 1ps between the two channels.
In June 2006 the European Union research project "IPHOBAC" funded under the 6th Framework Program on "Information Society Technologies" (IST) started in cooperation with six leading academic and four industrial partners, e.g. Thales Alcatel and France Telecom. On the component level u²t will develop integrated 100GHz and 300GHz millimeter-wave photonic components for the generation, modulation and detection of mm-wave signals. These innovative components will support multiple high-frequency applications in broadband telecommunications, such as 100Gbit/s Ethernet or radio-over-fiber, as well as applications in security, radar, and instrumentation. In the following 3 years u²t plans to invest more than 1 Mio € into this project.