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A scheme for the direct conversion of millimeter and THz waves to optical signals is introduced. The compact device consists of a plasmonic phase modulator that is seamlessly cointegrated with an antenna. Neither high-speed electronics nor electronic amplification is required to drive the modulator. A built-in enhancement of the electric field by a factor of 35 000 enables the direct conversion of millimeter-wave signals to the optical domain. This high enhancement is obtained via a resonant antenna that is directly coupled to an optical field by means of a plasmonic modulator. The suggested concept provides a simple and cost-efficient alternative solution to conventional schemes where millimeter-wave signals are first converted to the electrical domain before being up-converted to the optical domain.

To cope with the high bandwidth requirements of wireless applications 1 , carrier frequencies are shifting towards the millimetre-wave and terahertz bands 2 – 5 . Conversely, data is normally transported to remote wireless antennas by optical fibres. Therefore, full transparency and flexibility to switch between optical and wireless domains would be desirable 6 , 7 . Here, we demonstrate for the first time a direct wireless-to-optical receiver in a transparent optical link. We successfully transmit 20 and 10 Gbit/s over wireless distances of 1 and 5 m at a carrier frequency of 60 GHz, respectively. Key to the breakthrough was a plasmonic mixer directly mapping the wireless information onto optical signals. The plasmonic scheme with its subwavelength feature and pronounced field confinement provides a built-in field enhancement of up to 90’000 over the incident field in an ultra-compact and CMOS compatible structure. The plasmonic mixer is not limited by electronic speed and thus compatible with future terahertz technologies.

In this paper, we demonstrate an integrated microwave phoneeded for beamtonics phased array antenna feeder at 60 GHz with a record-low footprint. Our design is based on ultra-compact plasmonic phase modulators (active area <2.5µm²) that not only provide small size but also ultra-fast tuning speed. In our design, the integrated circuit footprint is in fact only limited by the contact pads of the electrodes and by the optical feeding waveguides. Using the high speed of the plasmonic modulators, we demonstrate beam steering with less than 1 ns reconfiguration time, i.e. the beam direction is reconfigured in-between 1 GBd transmitted symbols.

Plasmonic modulators might pave the way for a new generation of compact low-power high-speed optoelectronic devices. We introduce an extremely compact transmitter based on plasmonic Mach-Zehnder modulators offering a capacity of 4 × 36 Gbit/s on a footprint that is only limited by the size of the high-speed contact pads. The transmitter array is contacted through a multicore fiber with a channel spacing of 50 μm.

The concept and performance of the first multiwavelength deep UV light-emitting-diode-based high-performance liquid chromatography (HPLC) absorbance detector are presented. In single-wavelength mode and with optical reference, the limit of detection (LOD) is comparable to conventional state-of-the-art HPLC absorbance detectors. In multiwavelength mode--at present up to eight wavelengths without optical reference--the LOD is about 10 times higher than in single-wavelength mode. Multiplexing and demultiplexing methods are used to separate chromatographic signals in multiwavelength mode and keeps the detector configuration simple and yet flexible. Depending on the operation mode, stray light is either totally negligible or controlled electronically and digitally.

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Reflective semiconductor optical amplifier (RSOA) fiber cavity lasers are attractive colorless, self-seeded, self-tuning, and directly modulatable sources for passive optical networks (PONs). They comprise of an RSOA in the optical network unit as the active element, a distribution fiber as the laser cavity, a waveguide grating router, and a common reflective mirror with the latter two positioned at the remote node. In this paper, we introduce a model and perform simulations to elucidate the recently discovered successful operation of this new PON source. The results are in agreement with experiments; the formation of a narrow laser spectrum with a relatively constant output power is seen despite a relatively broad passband window of the waveguide grating router. We further study mode competition and mode partition noise. It is shown that proper chromatic dispersion management can overcome mode partition noise limitations. The quality of the RSOA fiber cavity laser does not degrade when being directly modulated and as a result these highly multimode lasers offer an economic way to transport Gbit/s upstream data over kilometers of fiber in a wavelength division multiplexing-PON.