Source: Optics.org£»

    A new class of photonic systems for fixed-frequency millimetre-wave applications could be used in radar, instrumentation and communications.

    IPHOBAC, a three-year European project involving industrial and academic partners, is merging photonics and radio wave technologies to construct photonic devices in the millimetre-wave frequency range above 30 GHz.

    ¡°The millimetre-wave photonic (mmWP) technology can offer absolutely unique properties, such as ultra-wide tunability, extremely low phase noise or oscillator remoting,¡± Andreas Stohr, IPHOBAC coordinator, told optics.org. ¡°It has inherent features that cannot easily be achieved with other competing technologies or all-electric solutions, and could be a disruptive technology in multiple applications.¡±

    The project has developed packaged InP-based quantum dash mode-locked lasers emitting in the 1.5 µm range, generating frequencies from 24 GHz to 77 GHz. These devices generate a millimetre-wave tone featuring a very narrow linewidth, lower than 100 kHz, that is sufficient for use in wireless transmission.

    ¡°Another interesting feature is the very wide optical spectrum of about 13 nm that is generated with a -3dB bandwidth,¡± commented Stohr. ¡°This wide bandwidth makes it suitable for very short pulse generation. Using standard single mode fibre, we obtained a 480 fs pulse. Since the emitted power is 15 mW, the peak power of this pulse generator is very high.¡±

    Other systems under investigation by IPHOBAC include:

    • Tunable dual-mode InP-based DBR and DFB lasers operating at 1.55 µm for optical signal generation in the 30-300 GHz range.

    • T-ray transmitters, consisting of an InP-based photomixer integrated with a planar antenna. Packaged in fibre-optic package with a THz focusing lens, the transmitters can generate mm-waves from 30-325 GHz.

    • Packaged 100 GHz photodiodes, including a broadband package enabling operation from DC-110 GHz. ¡°To our knowledge these are the first packaged 1.55 µm photodetectors offering such broadband performance,¡± said Stohr.