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Position detection is a key function needed for monitoring patients with sleep-related movement disorders. Tools are urgently needed to obtain a detailed patient-friendly long-Term assessment of sleep-related movements in the home situation. We present an optical two-dimensional pressure sensing system for real-Time patient monitoring that is based on optical coupling between crossing polymer or plastic optical fibres (POFs) and can easily be placed under a mattress in a home environment. Because the system deploys a grid of standard 1 mm diameter Step Index PMMA POF, it is low-cost, robust, flexible, compact, waterproof, scalable, not affected by external electrical fields, nor does it generate any electrical fields. Moreover, an alternative simple pressure sensitive POF crossing construction, based on local fibre bending is presented, which is more sensitive and more robust than crossing fibres left intact.

An 80MHz, 256-QAM IEEE 802.11ac-compliant WLAN and 9 band 64-QAM LTE-A signals were successfully transmitted over a 50m PMMA GI-POF link. The LTE-A bands were transmitted with radio over POF technique. The WiFi signal was transmitted with an intermediate frequency over POF (IFoPOF) approach due to the POF bandwidth. The IF frequency and the power budget were optimized in order to minimize the EVM penalty induced by the optical link. The total throughput of the LTE-A and WiFi signals were equal to 605 Mb/s and 434Mb/s, respectively. This proves that POF is suitable for multi-standard in-home radio over fiber networks.

Millimeter wave (mmWave) communication is being seen as a disruptive technology for 5G era. In particular, 60GHz frequency band has emerged as a promising candidate for multi-Gbps connectivity in indoor and hotspot areas. In terms of network architecture, cloud radio access network (CRAN) has emerged as the most promising architectural alternative to enable efficient baseband processing and dynamic resource allocation in 5G communications. In this article, we propose micro-CRAN (mCRAN) -a multi-gigabit indoor network architecture which leverages availability of high bandwidth in 60GHz frequency band. We have discussed in detail about the requirements and research challenges for various system modules for mCRAN based network architecture. We have also investigated the feasibility of IEEE 802.11ad MAC protocol for the proposed mCRAN architecture. We discuss the challenges related to 60GHz beamforming, medium access mechanisms and network architecture, and propose solutions to address them.

High separation ratio between degenerate LP11 modes is demonstrated through a Fourier Optics simulation model using the binary phase plates. 20Gbit/s transmission of two LP11 modes without crosstalk compensation is realized over 10km Two-moded Fiber.

We demonstrate successful transmission of WiFi signals over 50m step-index plastic optical fibre with 1mm core diameter employing an eye-safe resonant cavity light emitting diode and an avalanche photodetector. The EVM performance of 4.1% at signal data rate of 150Mb/s is achieved.

A two-port ring-resonator circuit is studied theoretically. It is shown that superluminal and negative group velocity (vg) phenomena can occur in both a passive two-port ring-resonator circuit with loss and an active one with gain. We present numerical observations of temporal behavior of a Gaussian pulse passing through circuits having such properties. We also show that when the negative vg is ‘slow’ (|vg|<

We developed photodefined, multimode-fiber compatible waveguides based on epoxies. These waveguides will be embedded in backplane PCB’s for optical interconnect applications using 850 nm VCSELs as light sources. Apart from very low loss, the material selection took into account, PCB compatibility and low yellowing due to high temperature processing (for PCB lamination and soldering). The waveguides showed losses < 0.06 dB/cm at 832 nm and 633 nm. Their loss increase after aging (1 hr at 185 °C) was limited to 0.04 dB/cm at 850 nm. Waveguides realized on FR-4 (epoxyfiberglass)PCB material are demonstrated.

The fluorescent complex $Nd(TTA)_{3}Phen$ (TTA=thenoyltrifluoroacetone, Phen = 1, 10-phenanthroline), was doped into the host material 6-FDA epoxy (6-fluorinated-dianhydride cured epoxy). The room-temperature absorption spectrum of $N^{3}$ transitions was experimentally obtained, with which the Judd-Ofelt model was applied to determine the Judd-Ofelt parameters. These parameters are used to calculate the emission probabilities of transitions and branching ratios of the $Nd_{3}$ from the excited-state $^{4}F_{3/2}$ to lower-lying manifolds. The radiative lifetime of $^{4}F_{3/2}$ was obtained from the emission probabilities. The results of the analysis indicate this Nd (III) complex doped polymer material is promising to be used in planar waveguide lasers and amplifiers.

Photostabilization is a widely used post lithographic resist treatment process, which allows to harden the resist profile in order to maintain critical dimensions and to increase selectivity in subsequent process steps such as reactive ion etching. In this paper we present the optimization of deep UV-curing of 0,3-3.3 μm thick positive resist profiles followed by heat treatment up to 280 °C. The effectiveness of this resist treatment allows for metal mask free reactive ion etching with selectivity up to 6 for silicon structures, thermal silicon oxide and silicon oxynitride. This procedure is demonstrated by the results obtained in etching of various integrated optical structures.

$Al_{2}O_{3}$ and $Y_{2}O_{3}$ are both very promising host materials for active integrated optics applications such as rare-earth ion doped waveguide lasers. In this paper, a reactive co-sputtering process for stable, target condition-independent deposition of $Al_{2}O_{3}$ layers with high optical quality is discussed. The loss of as-deposited $Al_{2}O_{3}$ waveguides in the near infrared wavelength range was 0.3 dB/cm. Reactive ion etching of both $Al_{3}O_{2}$ and $Y_{2}O_{3}$ thin films for defining channel waveguide structures was investigated and compared using $CF_{4}/O_{2}, BCl_{3}, HBr$ and $CL_{2}$ inductively coupled plasmas.

Optical ring resonators (ORRs) are good candidates to provide continuously tunable delay in beam forming networks (BFNs) for phased array antenna systems. Delay and splitting/combining elements can be integrated on a single optical chip to form an OBFN. A state-of-the-art 1×8 OBFN chip has been fabricated in LPCVD waveguide technology. It is designed with 1 input and 8 outputs, between which a binary-tree topology is used. A different number of ORRs (up to 7) are cascaded for each output. In this paper, the principle of operation is explained and demonstrated by presenting measurements on the 1×8 OBFN chip.

In this paper we show how the evanescent field of a localized mode in a photonic crystal micro-cavity can be perturbed by a nano-sized AFM tip. Due to the high field intensities in the cavity, we can see a significant change in output power when the tip is brought into the evanescent field in either contact or tapping mode operation. We find a 4 dB modulation, when using a $Si_{3}N_{4}$ tip and we show that the transmittance can be tuned from 0.32 to 0.8 by varying the average tapping height.

A laterally coupled electro-optic polymer microring resonator was designed and fabricated. The design consists of microrings of 200 μm radius with racetrack structures to improve the coupling between the bus waveguide and the ring. Two different fabrication schemes namely reactive ion etching (RIE) and photodefinition are presented. Thermally grown siliconoxide on conducting silicon was used as the bottom cladding. Passive ring resonance behavior has been demonstrated around 1550 nm. The through port response of the ring showed a maximum extinction of about 12 dB and a finesse of 6.

In this paper we report the ultrafast all-optical wavelength conversion in Silicon-on-Insulator (SOI) waveguides. We used a pump-probe setup with 300 femtosecond pulses to demonstrate large temporal phase-shifts, caused by the Kerr effect and free carrier generation. Large wavelength shifts of a 1683nm probe signal have been observed. The wavelength conversion, ranging from 10nm redshifts to 15nm blueshifts, depending on the time delay between the pump and probe pulses, is caused by the pump induced Cross Phase Modulation. Furthermore, an all-optical switching scheme using SOI microring resonators is discussed. These results enable ultrafast all-optical switching using SOI microring resonators.

A defect grating in a silicon on insulator waveguide is simulated. We consider spectral changes in the optical transmission when a thin silicon nitride or silicon tip is scanned across the defect. The tip perturbs the resonance field, moving its peak wavelength andpossibly changing its shape and quality factor. For the nitride tip, the influence is mostly a spectral shift; for silicon, the change of the resonance shape is pronounced. In particular for the nitride tip we observe a close correspondence between the wavelength shift as a function of tip position, and the local intensity in the unperturbed structure.

Novel optical signal processing techniques are reported to surmount the bandwidth restrictions of multimode fibre networks. Mode group diversity multiplexing integrates a variety of independent broadband services in a single fibre infrastructure. Optical frequency multiplying enables to carry microwave signals which considerably exceed the bandwidth of the multimode fibre network. These techniques create versatile easy-to-install multimode (polymer) optical fibre networks integrating broadband wirebound and wireless services.

Optical frequency multiplying using wavelength sweeping and a periodic bandpass filter enables multimode POF networks to transport microwave signals far beyond their bandwidth. Simulations show the capability to carry 16-QAM 56 Mbit/s wireless LAN signals at 5.4 GHz

By applying fast sweeping of the laser wavelength at the headend station and a multi-passband optical filter at the antenna stations, multi-GHz signals can be distributed cost-effectively using GIPOF links in a wireless LAN. Data signal transparency and simple antenna stations are obtained. First simulations have shown the feasibility of the system concept.