ProjectIPHOBAC Project

ContactQin Wang
IPHOBAC Project

The goal of this project is developing the components for wireless connections in the extra-high frequency bands running from 30GHz to 300GHz.

Since 2007 Acreo has been involved in an EU project IPHOBAC (Integrated photonic mm-wave functions for broadband connectivity), which was funded under the Sixth Framework Programme (FP6) with EUR 5.7 million. The project consortium has 11 partners from Germany, Spain, France, Slovenia, Sweden and the UK, which are active in research, academia and industry.
The success of the project helps fully develop millimetre-wave photonics components and integrated functions, and also make them available for the industry. The IPHOBAC-enabled functions will benefit a number of applications such as broadband communications, radar, security and instrumentation.

Acreo’s task in the project was to fabricate two monolithically integrated components, an analog optical transmitter and an analog optical transceiver. The transmitter was fabricated by monolithic integration of a DFB laser and a travelling wave electro-absorption modulator (DFB TW-EAM), and the transceiver was composed by a semiconductor optical amplifier (SOA) and a reflective electro-absorption transceiver (EAT).

This was a heavy clean-room process related work, and faced many tremendous technique challenges, such as 4 times epi growth and overgrowth, butt-joint interface, nano-scale DFB grating processing, precisely control of NiCr impendence matching resistor, BCB and Au electrode plating related process steps and so on. Two fabricated device examples are illustrated in figure 1 (a) and (b), respectively. Figure 2 shows a SOA-EAT module packed by IPHOBAC partner U2T. The SOA–EAT can function as a bidirectional interface between a wireless and a fiber optical network. It is worth to note that the EAT can either function as a transmitter (reflective modulator) or as a receiver (photodetector) depending on operation mode.

The device performance was characterized at Photonics and Microwave Engineering (FMI), KTH. Figure 3 shows the transmitter response of the packaged SOA–EAT measured with a 50 GHz PIN detector (a) and the microwave gain of the SOA–EAT as receiver compared with the 50 GHz detector (b). Both were measured for three different SOA currents using an external 1550 nm laser delivering −0.27 dBm input power to the SOA–EAT.

More information on IPHOBAC project can be found through www.ist-iphobac.org /, Acreo’s related work on above integrated components can be provided by Qin Wang

Publication

Andy Zhang, Qin Wang, Stefan Karlsson, Olle Kjebon, Richard Schatz, Pierre-Yves Fonjallaz, Susanne Almqvist, Marek Chacinski, Lars Thylen, Jesper Berggren, Mattias Hammar, Jorg Honecker and Andreas Steffan, ‘‘Fabrication of an electro-absorption transceiver with a monolithically integrated optical amplifier for fiber transmission of 40–60 GHz radio signals’’, Semicond. Sci. Technol. Vol.26, 014042 (2011).