PurposeThe purpose of this paper is to present the need, and a potential solution, for in‐plane routing of optical signals for optical‐enabled circuit boards.Design/methodology/approachMultimode waveguides and integrated 45° in‐plane mirror structures were made in a low loss acrylate‐based photopolymer using excimer laser ablation. The fabrication of multimode waveguides and mirrors was carried out in a single laser system which minimised alignment issues.FindingsIt was established that in‐plane mirror fabrication using laser ablation can be achieved and can potentially be used to define mirrors in waveguides made by other methods such as photolithography.Research limitations/implicationsWhile the concept (integrated in‐plane mirror) was demonstrated, the viability of its deployment will depend on the results of optical loss measurements for which further research is required.Originality/valueThe paper gives an overview of the design concept and fabrication steps for an in‐plane embedded mirror.

In Oxycarbidglasern werden die zweiwertigen Sauerstoffatome der SiO2-Tetraeder partiell durch den vierwertigen Kohlenstoff ersetzt, so das verbesserte thermische und mechanische Eigenschaften der Glaser und eine erhohte Resistenz gegen Kristallisation erwartet werden. Oxycarbidglaser weisen Bruchspannungen von 150+-85 MPa bis 550 +- 230 MPa und E-Moduli im Bereich von 100-110 GPa auf. Die thermischen Ausdehnungskoeffizienten liegen bei ca. 3x10 -6 / K und fur die dielektrische Konstante wird ein Wert von 4,4 bei einem dielektrischen Verlustfaktor von ca. 0,1 im Frequenzbereich von 10 Hz bis 10 kHz angegeben. Diese Kenndaten der Oxycarbidglaser lassen Anwendungen als Substrate in der Mikroelektronik und fur Laminate mit erhohter Festigkeit als moglich erscheinen. Derzeit gibt es jedoch uber Sol-Gel keine Technologie zur Herstellung grosformatiger Folien oder anderer groser Formkorper. Das Ziel der Untersuchungen bestand daher darin, ein Verfahren zur Herstellung von Siliciumoxycarbidglasfolien im Labormasstab zu entwickeln und die mechanischen und dielektrischen Eigenschaften der Folien als Funktion der Synthese- und Prozesparameter zu untersuchen.

Purpose The purpose of this paper is to provide an overview of the research in a project aimed at developing manufacturing techniques for integrated optical and electronic interconnect printed circuit boards (OPCB) including the motivation for this research, the progress, the achievements and the interactions between the partners. Design/methodology/approach Several polymer waveguide fabrication methods were developed including direct laser write, laser ablation and inkjet printing. Polymer formulations were developed to suit the fabrication methods. Computer‐aided design (CAD) tools were developed and waveguide layout design rules were established. The CAD tools were used to lay out a complex backplane interconnect pattern to meet practical demanding specifications for use in a system demonstrator. Findings Novel polymer formulations for polyacrylate enable faster writing times for laser direct write fabrication. Control of the fabrication parameters enables inkjet printing of polysiloxane waveguides. Several different laser systems can be used to form waveguide structures by ablation. Establishment of waveguide layout design rules from experimental measurements and modelling enables successful first time layout of complex interconnection patterns. Research limitations/implications The complexity and length of the waveguides in a complex backplane interconnect, beyond that achieved in this paper, is limited by the bend loss and by the propagation loss partially caused by waveguide sidewall roughness, so further research in these areas would be beneficial to give a wider range of applicability. Originality/value The paper gives an overview of advances in polymer formulation, fabrication methods and CAD tools, for manufacturing of complex hybrid‐integrated OPCBs.

The next major challenges for lab-on-a-chip (LoC) technology are 1) the integration of microfluidics with optical detection technologies and 2) the large-scale production of devices at a low cost. In this paper the fabrication and characterisation of a simple optical LoC platform comprising integrated multimode waveguides and microfluidic channels based on a photo-patternable acrylate based polymer is reported. The polymer can be patterned into both waveguides and microfluidic channels using photolithography. Devices are therefore both quick and cost-effective to fabricate, resulting in chips that are potentially disposable. The devices are designed to be highly sensitive, using an in-plane direct excitation configuration in which waveguides intersect the microfluidic channel orthogonally. The waveguides are used both to guide the excitation light and to collect the fluorescence signal from the analyte. The potential of the device to be used for fluorescence measurements is demonstrated using an aqueous solution of sodium fluorescein. A detection limit of 7 nM is achieved. The possibilities offered by such a device design, in providing a cost-effective and disposable measurement system based on the integration of optical waveguides with LoC technology is discussed.

Time resolved fluorescence emission from erbium doped silicate channel waveguides is studied using an established model for homogeneous cooperative upconversion. Each sample was fabricated using only a single sol-gel deposition for each of the core and cladding layers. As a result of the analysis, values of 1.7×10−17 and 1.4×10−17cm3∕s are reported for the homogeneous cooperative upconversion constant that governs the interaction of homogeneously distributed erbium ions in the I13∕24 state. The values reported here are found to be in agreement with those reported in other predominantly silica based glasses.

In this paper we present erbium absorption, gain, fluorescence lifetime and waveguide loss characterisation results for erbium doped waveguide amplifiers (EDWAs) fabricated using a single sol-gel deposition for each of the core and cladding layers.

We present the results of optical-characterization experiments conducted on optically active erbium-doped waveguides. Using selected characterization results presented in this paper and a simple analysis, the device operation is evaluated. Each of the core and the cladding layers were individually fabricated using a single sol-gel deposition. These are, to the best of our knowledge, the first optically active waveguides to be fabricated in such a way. Characterization results include gain, fluorescence-lifetime, waveguide-loss, polarization-dependent-loss (PDL), and erbium-absorption measurements. Relative gains of over 1 dB/spl middot/cm/sup -1/ were measured. Fluorescence lifetimes of the /sup 4/I/sub 13/2/ /spl rarr/ /sup 4/I/sub 15/2/ transition as high as 5.6 ms were observed. Waveguide losses as low as 0.13 dB/spl middot/cm/sup -1/ were measured.

Introduction: The use of optics in modem avionic systems is increasing. In the emerging integrated modular avionics (IMA) architectures it is envisaged that most of the intra-cabinet and cabinet-suhsystem interconnections for the System Area Network onboard an aircraft, will be made using optical links. It is also envisaged that large numbers of relatively modestscale, compact crosspoint switches will be at the core of this implementation, to provide the required dynamic reconfiguration. The work reported here describes the construction of a 4 x 4 optoelectronic crosspoint switch demonstrator. At the heart of this demonstrator is a custom high-speed electronic crosspoint chip with integrated receiver and laser driver circuitly. The Optical Chip Carrier (OCC) approach, shown in figure 1, has been developed as an integration and packaging platform to enable the compact assembly of the optoelectronic interface devices (detectors and VCSELs) with the highperformance crosspoint chip and the optical inputloutput connections. The footprint of the OCC is dominated by the size of the fibre ribbon connectors.

The devices and the integration platform for the assembly of a 4 × 4 optoelectronic crosspoint switch have been described. We will report on the performance of the mirror structures and bumps, and on the progress made in the assembly, and testing of the switch.

Development of a novel multifunctional acrylate based photo-polymer formulation with T/sub g/ >150/spl deg/C and its application in the fabrication of optical waveguides is reported. Single mode planar optical waveguides were fabricated using UV exposure through a mask followed by development. Waveguide losses at 1550, 1300 and 850 nm as measured using cutback method were 0.7, 0.4 and 0.05 dB/cm respectively. Birefringence in polymer films was around 1 /spl times/ 10/sup -3/. Waveguides subjected to 85/spl deg/C, under 85% relative humidity conditions showed no deterioration or delamination.

The performance of a novel multifunctional acrylate based photo-polymer is presented. Rapid direct writing of multimode (50 μm square core) cladded waveguides, compliant bumps for flip-chip bonding and 45° total internal reflection mirrors for out of plane coupling have been realised using a high-power 325 nm He:Cd laser with high precision and repeatability. The losses are measured to be less than 0.17 dB/cm at 850 nm and less than 0.5 dB/cm at 1300 nm by cutback method. This custom multifunctional acrylate co-polymer has been found to be thermally stable up to a temperature of 300° as determined using DTA–TG analysis.