Gian-Luca Bona

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SiON high-refractive-index waveguide and planar lightwave circuits The rapidly growing optical communication market requires photonic components with ever-increasing functionality and complexity that can be fabricated reliably at low cost. Of the various approaches used to fabricate photonic components, those based on planar waveguides have achieved high(More)
—To reduce the coupling loss of a fiber-to-ridge wave-guide connection, a planar silica spot-size converter for a wavelength of 1.55 m is implemented in the form of a nonpe-riodic segmented waveguide structure with irregular tapering. A simple single-step lithography process is sufficient for the fabrication of the planar structures. An evolutionary(More)
In this paper, different polymer optical fibres for applications in force sensing systems in textile fabrics are reported. The proposed method is based on the deflection of the light in fibre waveguides. Applying a force on the fibre changes the geometry and affects the wave guiding properties and hence induces light loss in the optical fibre. Fibres out of(More)
In this paper, a textile-based respiratory sensing system is presented. Highly flexible polymeric optical fibres (POFs) that react to applied pressure were integrated into a carrier fabric to form a wearable sensing system. After the evaluation of different optical fibres, different setups were compared. To demonstrate the feasibility of such a wearable(More)
In this paper, a textile-based sensing principle for long term photopletysmography (PPG) monitoring is presented. Optical fibers were embroidered into textiles such that out-coupling and in-coupling of light was possible. The "light-in light-out" properties of the textile enabled the spectroscopic characterization of human tissue. For the optimization of(More)
We report on the fabrication of a grating-based add–drop filter in SiON planar waveguide technology. We achieved apodization of the Bragg grating by concatenating subgratings with various duty cycles. We present the theoretical and experimental dependence of the coupling coefficient on the duty cycle, which leads to a minimum coupling coefficient of 30%.(More)
We study the effect of a spiral corrugation on the outer surface of a fully metal-coated scanning near-field optical microscopy (SNOM) probe using the finite element method. The introduction of a novel form of asymmetry, devoid of any preferential spatial direction and covering the whole angular range of the originally axisymmetric tip, allows attaining(More)
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