Netsanet Merawi Tessema

We report a multicast switch PIC serving as a transponder aggregator. Successful data transmission through InP multicast switch and reception in a fully packaged coherent receiver demonstrates the drop traffic flow of a ROADM node.

Loss-less nodes based on semiconductor optical amplifiers to enable add/drop functionalities are studied in order to preserve the traffic throughput when adopting high-capacity multicarrier signal formats in metropolitan area networks.

We assess the performance of a modular photonic integrated circuit (PIC) for space and time optical switching as an optical add-drop node for metro-access network applications. The PIC based on semiconductor optical amplifier (SOA) technology enables the implementation of compact, low cost and lossless add-dropping through fast optical switching. D...

We demonstrate a C-band optical cross-connect switch based on InP integrated photonics, butt-coupled to a silica PLC for facile optical alignment. The switch allows the development of low power, low latency and low-cost WDM-switches.

The impact of the crossing of SOA-based MAN nodes on DMT high-capacity transmission is experimentally evaluated. We provide an optimization of the saturation levels of the SOAs enabling add/drop functionalities to preserve the transmitted throughput.

Photonic WDM switches and photonic integrated WSS are designed as building blocks to realize novel modular metro node architectures. Advances in compact photonic integrated InP switches using the InP generic technology will be discussed.

A wide-scan and broadband focal-plane array (FPA) concept is introduced in this article, which provides high antenna gain and effective isotropic radiated power (EIRP) with electronic beamsteering within a relatively large field of view (FoV), up to +/-20°. The antenna uses a bifocal double-reflector concept that optimizes the illumination of the f...

The system performance of a photonic integrated WDM wavelength selective switch is assessed with 10, 20 and 40Gb/s NRZ-OOK. Results show lossless operation, limited penalty for 8 WDM channels and > 8dB power dynamic range.

We demonstrate a hybrid radio-optical wireless communication system using a photonic integrated all-optical-cross-connect (OXC) chip to realize a highly reconfigurable and reliable bidirectional indoor wireless network which provides the ultimate capacity per user. By remote wavelength-tuning, narrow optical beams are directed to the users employin...

Beam forming using a 4x1 phased array with an optical feed network for K-band smart antenna systems is presented. Up to 45 degree steering angles are achieved. Wireless transmission throughputs of up to 3 Gbit/s using 32-OFDM subcarriers are achieved for the attained steering angles.

An optimized double-reflector antenna concept for a wideband focal plane array (FPA) configuration is presented for Ka-band applications with a limited scan range, e.g. ground terminals for satellite communication. The proposed reflector configuration allows to maximize the number of active array elements and minimize the actual array size during s...

An optically controlled multi-RF beamformer for targeting more than one satellite is presented. Two beams in K-band of 6 Gbps each are generated by a 2x1 beamformer attached to a wavelength-dependent ring-based optical chip.

The use of a 35 GHz reflective electroabsorption modulator (REAM) monolithically integrated with a semiconductor optical amplifier (SOA) for indoor wideband analogue applications is demonstrated. Unlike REAMs, good performances over a wide range of input optical power and wavelength are observed, which mitigates the need for accurate control of the...

Millimeter wave (mm-wave) beam steering is a key technique for the next generation (5G) wireless communication. 28-GHz and 38-GHz bands are widely considered as the candidates for 5G. In the context of indoor coverage, fiber-wireless systems with multiple simplified remote antenna sites are attractive to avoid the indoor coverage problem caused by...

In this paper we present the design, realization, and experimental characterization of a photonic integrated true time delay circuit on a CMOS-compatible Si <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sub> N <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/...

Utilizing an InP membrane based cascaded acceptance optical receiver (CAO-Rx), we demonstrate 17.4Gbps optical wireless transmission in C-band. By separating light collection and opto-electrical conversion, CAO-Rx provides better optical efficiency and electrical bandwidth simultaneously.

A 38GHz beam steered fiber-wireless system, enabled by a novel integrated optical tunable delay line, is demonstrated for 5G indoor coverage. The beam steering gains 14dBm spatial power focusing and 6 times EVM improvement.

We designed and fabricated a Silicon Nitride (Si3N4) photonic integrated circuit targeting wideband two-dimensional radio beamforming from 20–40 GHz for satellite communications. Continuous true time delay tunability is achieved by using thermo-optic phase shifters in a 2-port optical ring resonator. Scanning angles up to 20° and true time delay ba...

A compact and fabrication-tolerant integrated remotely tunable optical delay line is proposed for millimeter-wave beam steering and is fabricated in an InP generic foundry. The proposed delay line is based on a spectrally cyclic-arrayed waveguide grating feedback loop. Its major features include the tolerant architecture with reduced chip size, and...

We designed, fabricated and tested a compact AWG-based true-time delay chip for optically-assisted radio beamforming. Beam steering is performed remotely by only tuning the laser wavelength. We demonstrated beamforming of a 2.5-Gbps, 10 GHz signal with 2.7 o /nm discrete-step beam steering.

The electrically-controlled optical phase shifter (ECO-PS) is proposed and experimentally investigated for broadband radio orbital angular momentum mode generation. ECO-PS can offer the same advantages as optical true time delay schemes while avoids their phase-frequency dependence.

Optical true time delay (OTTD) is an attractive way to realize microwave beam steering (MBS) due to its inherent features of broadband, low-loss, and compactness. In this Letter, we propose a novel OTTD approach named cyclic additional optical true time delay (CAO-TTD). It applies additional integer delays of the microwave carrier frequency to achi...

This paper gives an overview of research within the ALADIN project, which aims to develop an assistive vocal interface for people with a physical impairment. In contrast to existing approaches, the vocal interface is trained by the end-user himself, which means it can be used with any vocabulary and grammar, and that it is maximally adapted to the...

Distributed Beamforming conserves power consumption of wireless sensor networks and extends communication range by focusing the transmit signal energy in the direction of the receiver. Significant saving of power consumption is obtained by only selecting the optimal number of nodes prior to beam forming which are necessary to form the communication...

In wireless cognitive sensor networks the number of cognitive nodes for distributed beamforming should be large in order to reduce interference to primary users. The available optimal numbers of nodes selection schemes of distributed beamforming techniques do not address the cognitive radio scenarios and minimization of interference in the directio...