100 Gb/s uncooled WDM system using conventional WDM components and advanced receiver signal processing

We demonstrate an uncooled WDM system using standard WDM components and receiver signal processing, with a different number of receivers to transmitters, to allow wide temperature drift of the transmitter lasers. A 100 Gb/s 8-wavelength demonstrator has been developed, which proves the feasibility of the approach over 25 km of SMF. © 2012 OSA.

Characteristics of the spectral dynamics of picosecond modulated AlGaAs/GaAs injection lasers

Breakdown of the optical spectrum of a train of picosecond pulses into components with a distance which exceeds kT (200 cm-1 at λ = 955 nm and T = 300 K) is discovered for the first time in an injection laser. The effect may be caused by combined interaction between photons and phonons, with collective excitations in the degraded electron-hole GaAs plasma, and with the stream of drifting carriers in the active medium of the laser.

Energy performance certification as a signal of workplace quality

Energy performance labelling and certification have been introduced widely to address market failures affecting the uptake of energy efficient technologies, by providing a signal to support decision making during contracting processes. The UK has recently introduced the Energy Performance Certificate (EPC) as a signal of building energy performance. The aims of this article are: to evaluate how valid EPC's are signals of occupier satisfaction with office facilities; and to understand whether occupant attitudes towards environmental issues have affected commercial office rental values. This was achieved by surveying occupant satisfaction with their workplaces holistically using a novel multi-item rating scale which gathered 204 responses. Responses to this satisfaction scale were matched with the corresponding EPC and rental value of occupier's workplaces. The satisfaction scale was found to be both a reliable and valid measure. The analysis found that EPC asset rating correlates significantly with occupant satisfaction with all facility attributes. Therefore, EPC ratings may be considered valid signals of overall facility satisfaction within the survey sample. Rental value was found to correlate significantly only with facility aesthetics. No evidence suggests rental value has been affected by occupants' perceptions towards the environmental impact of facilities. © 2013 The Authors.

Degenerate mode-group division multiplexing using MIMO digital signal processing

MIMO DSP is employed to improve the performance of degenerate mode-group division multiplexing in 8 km of conventional GI-MMF. Compensation of the mode coupling, induced by the launch and propagation, between and inside each degenerate mode-group is investigated in order to reduce the DSP complexity. © 2013 IEEE.

Identification of the steering control behaviour of five test subjects following a randomly curving path in a driving simulator

The paper is concerned with the identification of theoretical preview steering controllers using data obtained from five test subjects in a fixed-base driving simulator. An understanding of human steering control behaviour is relevant to the design of autonomous and semi-autonomous vehicle controls. The driving task involved steering a linear vehicle along a randomly curving path. The theoretical steering controllers identified from the data were based on optimal linear preview control. A direct-identification method was used, and the steering controllers were identified so that the predicted steering angle matched as closely as possible the measured steering angle of the test subjects. It was found that identification of the driver's time delay and noise is necessary to avoid bias in identification of the controller parameters. Most subjects' steering behaviour was predicted well by a theoretical controller based on the lateral/yaw dynamics of the vehicle. There was some evidence that an inexperienced driver's steering action was better represented by a controller based on a simpler model of the vehicle dynamics, perhaps reflecting incomplete learning by the driver. Copyright © 2014 Inderscience Enterprises Ltd.

Integration of silicon plasmonic schottky photodetector for on chip signal tapping at telecom wavelengths

We experimentally demonstrate the use of an on-chip integrated Schottky plasmonic detector for testing, monitoring and tapping signals in plasmonic and photonic devices. Theoretical model and measurement of external and integrated devices will be presented. © OSA 2013.

Integration of silicon plasmonic schottky photodetector for on chip signal tapping at telecom wavelengths

We experimentally demonstrate the use of an on-chip integrated Schottky plasmonic detector for testing, monitoring and tapping signals in plasmonic and photonic devices. Theoretical model and measurement of external and integrated devices will be presented. © OSA 2013.

Integration of silicon plasmonic schottky photodetector for on chip signal tapping at telecom wavelengths

We experimentally demonstrate the use of an on-chip integrated Schottky plasmonic detector for testing, monitoring and tapping signals in plasmonic and photonic devices. Theoretical model and measurement of external and integrated devices will be presented. © OSA 2013.

100 Gb/s uncooled WDM system using conventional WDM components and advanced receiver signal processing

We demonstrate an uncooled WDM system using standard WDM components and receiver signal processing, with a different number of receivers to transmitters, to allow wide temperature drift of the transmitter lasers. A 100 Gb/s 8-wavelength demonstrator has been developed, which proves the feasibility of the approach over 25 km of SMF. © 2012 Optical Society of America.

20 Gb/s QPSK transmission using an electro-optically modulated vertical-cavity surface-emitting laser

20 Gb/s QPSK transmission over 100 m of OM3 fibre using an EOM VCSEL under QPSK modulation is reported. Bit-error-ratio measurements are carried out to express the quality of the transmission scheme. © 2011 Optical Society of America.

Chirp-enhanced direct modulation of a monolithic sub-Terahertz dual laser transmitter

A technique enabling 10 Gbps data to be directly modulated onto a monolithic sub-THz dual laser transmitter is proposed. As a result of the laser chirp, the logical zeros of the resultant sub-THz signal have a different peak frequency from that of the logical ones. The signal extinction ratio is therefore enhanced by suppressing the logical zeros with a filter stage at the receiver. With the aid of the chirp-enhanced filtering, an improved extinction ratio can be achieved at moderate modulation current. Hence, 10 GHz modulation bandwidth of the transmitter is predicted without the need for external modulators. In this paper, we demonstrate the operational principle by generating an error-free (bit error rate less than 10-9) 100 Mbps Manchester encoded signal with a centre frequency of 12 GHz within the bandwidth of an envelope detector, whilst direct modulation of a 100 GHz signal at data rates of up to 10 Gbps is simulated by using a transmission line model. This work could be a key technique for enabling monolithic sub-THz transmitters to be readily used in high speed wireless links. © 2013 IEEE.

Monolithic electro-optically modulated VCSEL suitable for radio over fibre applications to 20 GHz

An integrated EOM VCSELs is shown to offer high linearity (92dB/Hz2/3 at 6GHz) and by extrapolation ~90dB/Hz2/3 up to 20GHz. Successful modulation with IEEE 802.11g signals is demonstrated at 6GHz with a 12dB dynamic range. © OSA/OFC/NFOEC 2011.

Residual strength of GRP laminates with multiple randomly distributed fragment impacts

The residual tensile strength of glass fibre reinforced composites with randomly distributed holes and fragment impact damages have been investigated. Experiments have been performed on large scale panels and small scale specimens. A finite element model has been developed to predict the strength of multi-axial panels with randomly distributed holes. Further, an effective analytical model has been developed using percolation theory. The model gives an estimation of the residual strength as function of removed surface area caused by the holes. It is found that if 8% of the area is removed, the residual strength is approximately 50% of the un-damaged strength. © 2014 Published by Elsevier Ltd.