Design of spectrometers and polarization splitters using adiabatically connected slab waveguides

The design of fully integrated prism spectrometers and polarization splitters in adiabatically connected slab waveguides with two different thicknesses, using principles of geometrical optics, is presented. In addition, the design of mirrors to connect these devices to input and output waveguides is discussed. The proposed structures will be fabricated, using two wet-etching steps, in a Si3N4 layer in-between a buffer and cladding SiO2 layer

Light Turning Mirrors in SiON Optical Waveguides for Hybrid Integration with CMOS Photo-detectors

A new method is proposed for hybrid integration of SiON optical waveguides and standard CMOS photo-detectors based on anisotropic etching of 45° facets in a Si substrate. After removal of anisotropically etched Si structures in cladding SiO2, the fabricated total-internal-reflection mirrors can direct the output of the waveguides to photo-detectors placed on top of the chip. The metal-free fabrication process, designed to create these mirrors, is convenient for batch production. Fourier optics based simulations predict that the reflection efficiency of the mirrors is 68.5 %. The far field pattern obtained from the fabricated device is similar to the simulated one

45° light turning mirrors for hybrid integration of silica optical waveguides and photo-detectors

For hybrid integration of an optical chip with an electronic chip with photo diodes and electronic processing, light must be coupled from the optical chip to the electronic chip. This paper presents a method to fabricate metal-free 45° quasi-total internal reflecting mirrors in optical chips that enable 90° out-of-plane light coupling between flip-chip bonded chips. This method is fully compatible with fabrication of conventional optical chips. The mirrors are created using anisotropic etching of 45° facets in a Si substrate followed by fabrication of optical structures. After removal of the mirror-defining Si structures by isotropic etching, the obtained air-optical structure interface directs the output of the waveguides to out-of-plane photo detectors that are mounted flip-chip on the optical chip. Simulations show a reflection efficiency of 72.3 %, while experimentally 47% was measured on a not fully optimized first batch

Use of integrated optical waveguide probes as an alternative to fiber probes for sensing of light backscattered from small volumes

We show that for light collection from thin samples, integrated probes can present a higher efficiency than conventional fiber probes, despite having a smaller collection area. Simulation results are validated by experiments

Els camins del present, viatges pel passat i el futur

La temàtica sobre la qual el Dr. Riera i Tuèbols ha escrit al llarg de la seva trajectòria professional és àmplia i diversa i, per tant, múltiples poden ser les refl exions al voltant del pensament i la seva obra. Aquest volum n’és una mostra. Cal assenyalar que aquesta diversitat temàtica no és aleatòria, sinó el resultat d’una concepció holística de la cultura que li ha permès eliminar les fronteres entre aspectes aparentment allunyats com l’origen de l’Univers, la il·lustració, la fi losofi a de la natura, la bioètica o la Segona Guerra Mundial..

Reflection of semi-guided plane waves at angled thin-film transitions

The propagation of thin-film guided, in-plane unguided plane optical waves, and their partial or total reflection at transitions between regions with different film thickness, is considered. The properties of reflected and refracted waves can be predicted reasonably by readily available Helmholtz- and/or eigenmode-solver

Integrated waveguide probes for efficient backscattered-light collection from thin samples

The higher performance of integrated waveguide probes, with respect to fiber probes, in the collection of light backscattered from thin samples is demonstrated by means of a semi-analytical model, which is validated by experimental results

Efficiency comparison between integrated optical waveguide probes and conventional fiber probes in the detection of backscattered light

Multimode silicon-oxynitride (SiON) waveguide structures are investigated for probing fluorescence and backscattered light from samples of different thicknesses. The collection efficiency together with the resolution of such probes is compared to that of a conventional fiber probe. The simulation results show that, in case of low scattering samples, among the two types of probes the former present higher collection efficiencies when the sample thickness is below 85 µm. The analytical model developed to estimate the collection efficiency of the integrated probes was validated experimentally through fluorescence measurements carried out on a ruby rod. The model and the experimental results are both presented in this work

Integrated optical microsystems: guiding light into the future

At the Integrated Optical Microsystems (IOMS) Group of the University of Twente, we are working towards setting the basis for the future of on-chip nanophotonics. In the following sections, our work on on-chip lasers and amplifiers, optical waveguide devices for different applications such as medical imaging and sensing as well as photonics-electronics integration technologies will be detailed