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The authors present the design, fabrication and characterisation of passive photonic components using InP optical wire technology. These components are straight and curved waveguides as well as Y-junctions. Their ultimate use is to be integrated within active nanophotonic functions and this is implicitly targeted in the different parts of this process work. First, propagation and excess losses because of a bend or Y-junction are modelled using a beam propagation method or a finite difference time domain method. Then, the technological process used to fabricate these components is presented; it is mainly based on e-beam direct writing and inductively coupled plasma deep etching. Finally, the different losses are measured and results are compared with the theory. The authors demonstrate, thus, that the use of submicron waveguides (or optical wire) can lead to very compact optical passive functions on InP since very small radius bends and wide angle Y-junctions showed almost low excess loss. [ABSTRACT FROM AUTHOR]

Two optically controlled phase shifters are proposed. The first structure is based on the microstrip ring resonator inserted between two gaps. Phase-shifting is performed by optically controlling the gaps capacitance. The structure has shown excellent characteristics, however the rejection rate is high. To minimise the reflected power, the second phase shifter, which is based on the rat race coupler, is proposed. In this case, the phase-shifting is performed by adding extra lengths to two gaps, judiciously placed along the microwave ports. The gaps act as short-circuits under sufficient illumination conditions. At 10 GHz, the structure provides a continuous variation of Δϕ(S21) between 0 and 90°, with Δ|S21| less than 5dB. On a 500 MHz band around 10 GHz, the phase variation is less than 5%. |S11| keeps <⁕20 dB within the experimental bandwidth 8.9–10.7 GHz. Both structures were fabricated on high-resistivity silicon substrate and the experimental results confirm the three-dimensional electromagnetic simulations. [ABSTRACT FROM AUTHOR]

A report is presented on the optical propagation loss of waveguides based on InP nanowires embedded in a benzocyclobutene matrix and fabricated through a wafer bonding process. Propagation loss was evaluated on waveguides of varying width; it can be as low as 0.8 dB/mm for a 300×300 nm InP. [ABSTRACT FROM AUTHOR]

The fabrication and propagation loss measurement of GaAs/polymer optical nanowires are reported. Their design consists of a 300×300 nm cross-section GaAs core buried into a polymer matrix bonded on a Si host substrate. The propagation loss at λ=1.55 µm is measured as about 5 dB/mm for both polarisations. [ABSTRACT FROM AUTHOR]

An adhesive wafer bonding technique for the fabrication of nanophotonic guiding structures, the design of which consists of a III-V semiconductor core buried in a polymer matrix, is reported. The bonding was realised owing to benzocyclobutene. Nanostructures are perfectly embedded in the void-free matrix to form high density photonic circuits. [ABSTRACT FROM AUTHOR]

The work reported deals with the demonstration of the use of high modal bandwidth OM4 multimode fibre as multi-purpose transmission media for short-range indoor or outdoor applications taking advantage of the wavelength division multiplexing concept. Simultaneous transmission of a digital 10GbE signal and a radio-frequency multiband orthogonal frequency division multiplexing ultra-wide band (band group 5) signal at 480 Mbits has been successfully achieved over 1.1 km fibre length without any error and with relative constellation error (RCE) less than 5.5% rms, respectively. Concerning the radio signal, an additional 1 m-long wireless path has also been demonstrated that led to an overall RCE value of 7.2%. [ABSTRACT FROM AUTHOR]

A compact tune-all bandpass filter is presented. This electronically tuned filter is based on series-coupled slow-wave resonators. It allows wide simultaneous and continuous tunings of centre frequency (+/-15% around 0.7 GHz) and bandwidth (from 50 to 100 MHz) with insertion loss IL<5.4 dB and return loss RL>11 dB. This two-pole bandpass filter exhibits also a very small surface of only 7.3×10-3 λ02 and a -20 dB stop-band that extends up to 10 GHz. [ABSTRACT FROM AUTHOR]

The study of a monolithic multisection modelocked laser for millimetre (mm)-wave radio-over-fibre (RoF) links is reported. The longitudinal mode spectrum is studied, as is the evolution of the mode distribution with the injected current in the different sections. A stable dual-mode operation regime is identified and used to demonstrate the possibility of using this device as a compact transmitter in RoF systems incorporating optoelectronic upconversion through the injection of an intermediate frequency signal in the absorber section, while the 40 GHz mm-wave carrier is injected in the gain section. Characterisation of the modelocked laser in an analogue transmission experiment shows a spurious free dynamic range of 65 dB-Hz2/3. [ABSTRACT FROM AUTHOR]

Experimentally carrier-induced optical index, propagation excess loss and carrier lifetime variations against injected current in n+- InP/i-InGaAsP/iInP/p+-InP heterostructures are investigated. The heterostructures have quaternary bandgap composition of λd 1.18 and 1.30 μm, and they were specially designed for 1.55 μm wavelength digital optical switch (DOS) applications. The Q130 based heterostructure shows the best potential for high-performance DOS. [ABSTRACT FROM AUTHOR]

A radio-over-multimode-fibre system is used to achieve an indoor radio coverage solution for low cost 60 GHz WLAN. It is composed of a radio-over-fibre link based on a 300 in (or more) multimode fibre long link operating at 850 nm and a compact RF transceiver including a phase noise cancellation technique at 60 GHz. The system described can provide a low cost solution for high data rate (400 Mbit/s) distribution at 60 GHz. [ABSTRACT FROM AUTHOR]

The fabrication and characterisation of a GaAs based electroabsorption modulator for radio over fibre applications is reported. It is designed to work as a transmission type device for multimode fibre networks at 850 nm wavelength and to act so, it has been transferred to a transparent silica substrate (after complete removal of the GaAs substrate). [ABSTRACT FROM AUTHOR]

Mach­Zehnder type interferometer measurements are used to determine the variation of the optical index and propagation loss. Devices are fabricated in InGaAsP/InP material line and experiments are performed at 1.3 and 1.55 μm wavelength. Combining static and dynamic measurements, the carrier life-time, the effective index and loss variation against injected current and carrier density were determined. [ABSTRACT FROM AUTHOR]

The fabrication and characterisation of low-loss InGaAsP/InP optical submicron waveguides made with ICP etching is reported. Their width ranges from 0.2 to 2 µm. For the 0.5 µm width, the propagation losses at λ = 1.55 µm as low as 4.2 dB/mm have been measured. [ABSTRACT FROM AUTHOR]

Measures the variation of propagation effective index of integrated optics devices using an heterodyne detection scheme. Direct transfer of optical phase shift in the microwave frequency range allowing phase measurements using common microwave network; Application of the technique to a digital optical switch-technique based switch.