Polymer long-period raised rib waveguide gratings using nano-imprint lithography

This letter presents the fabrication and demonstration of a long-period raised rib waveguide grating using nano-imprint lithography. The device consists of a lower UV15 cladding, where relief-gratings are implemented, and an NOA73 raised rib core waveguide. Spectral transmission reveals a resonance at 1585 nm with about 10-dB rejection and 12-nm linewidth

High-Q wavelength division multiplexed optoelectronic oscillator based on a cascaded multi-loop topology

A WDM optoelectronic oscillator (OEO) based on a cascaded optical multi-loop configuration and multiple photodiodes is proposed and demonstrated experimentally. By employing up to three lasers widely separated in wavelength along with two cascaded multi-loop fiber sections and two photodiodes, we demonstrate OEO topologies that scale up to six effective loops revealing an ultra-high quality factor in excess of 1010 and a phase noise performance down to −119 dBc/Hz at 10 kHz offset

Optoelectronic oscillator based on class AB photonic link

An optoelectronic oscillator topology based on a class AB analogue optical link is proposed. The motivation for this approach is based on the unique property of class AB links for mitigating both shot noise and relative intensity noise contributions. The class AB optoelectronic oscillator is compared with a conventional single loop optoelectronic oscillator

Ultra-high-Q optoelectronic oscillator based on bilaterally coupled loops

An optoelectronic oscillator (OEO) based on bilateral coupling between two individual optoelectronic loops is demonstrated. The resulting OEO has two modes of operation, in which the individual loops either oscillate or act as IIR filters. A Q-factor greater than 1010 at 5.8 GHz is observed

Advanced 3R regenerator scheme for high spectral efficient signal waveforms

We propose a novel 3R regenerator architecture for highly spectral efficient signals. Through numerical simulations we evaluate its performance and compare with traditional 2R schemes. The results of the analysis demonstrate necessity of 3R for regeneration of NRZ pulses and its relevance for future high capacity transmission systems

Optoelectronic recirculating delay line implementation of a high-q optoelectronic oscillator

A dual-loop optoelectronic oscillator incorporating an optoelectronic recirculating delay line in order to circumvent the limitations of optical coherence associated with all-optical loops is demonstrated. The optoelectronic oscillator produces a very stable signal at 5.4 GHz (suitable for WLAN 802.11n and 4G-WiMAX systems) with a sub-Hz 3-dB bandwidth and a Q-factor in excess of 1010. A phase noise of -115 dBc/Hz is recorded at 10 kHz offset, owing to the reduction in phase induced intensity noise, whilst side modes are significantly suppressed for offset values in the range 100 kHz - 1 MHz

QPSK 3R regenerator using a phase sensitive amplifier

A black box phase sensitive amplifier based 3R regeneration scheme is proposed for non-return to zero quadrature phase shift keyed formatted signals. Performance improvements of more than 2 dB are achieved at the presence of input phase distortion

Translational neurophysiology in sheep:Measuring sleep and neurological dysfunction in CLN5 affected Batten disease sheep

This is the final published version of a paper originally published in BRAIN 2015: 138; 862?874, DOI: http://dx.doi.org/10.1093/brain/awv026Creating valid mouse models of slowly progressing human neurological diseases is challenging, not least because the short lifespan of rodents confounds realistic modelling of disease time course. With their large brains and long lives, sheep offer significant advantages for translational studies of human disease. Here we used normal and CLN5 Batten disease affected sheep to demonstrate the use of the species for studying neurological function in a model of human disease. We show that electroencephalography can be used in sheep, and that longitudinal recordings spanning many months are possible. This is the first time such an electroencephalography study has been performed in sheep. We characterized sleep in sheep, quantifying characteristic vigilance states and neurophysiological hallmarks such as sleep spindles. Mild sleep abnormalities and abnormal epileptiform waveforms were found in the electroencephalographies of Batten disease affected sheep. These abnormalities resemble the epileptiform activity seen in children with Batten disease and demonstrate the translational relevance of both the technique and the model. Given that both spontaneous and engineered sheep models of human neurodegenerative diseases already exist, sheep constitute a powerful species in which longitudinal in vivo studies can be conducted. This will advance our understanding of normal brain function and improve our capacity for translational research into neurological disorders.This work was funded by CHDI Inc. (AJM). Founding the\ud sheep flock, and costs in NZ relating to the rearing and\ud genotyping of the animals were funded by a series of grants\ud from the Neurological Foundation of NZ and the Batten\ud Disease Support and Research Association (DNP, NLM)

Simple geometric interpretation of signal evolution in phase-sensitive fibre optic parametric amplifier

Visualisation of complex nonlinear equation solutions is a useful analysis tool for various scientific and engineering applications. We have re-examined the geometrical interpretation of the classical nonlinear four-wave mixing equations for the specific scheme of a phase sensitive one-pump fiber optical parametric amplification, which has recently attracted revived interest in the optical communications due to potential low noise properties of such amplifiers. Analysis of the phase portraits of the corresponding dynamical systems provide valuable additional insight into field dynamics and properties of the amplifiers. Simple geometric approach has been proposed to describe evolution of the waves, involved in phase-sensitive fiber optical parametric amplification (PS-FOPA) process, using a Hamiltonian structure of the governing equations. We have demonstrated how the proposed approach can be applied to the optimization problems arising in the design of the specific PS-FOPA scheme. The method considered here is rather general and can be used in various applications