JePPIX : the platform for InP-based photonics

JePPIX is the European platform that offers ccess to Indium Phosphide based technology for proof of concept, prototyping and large volume manufacturing. This is enabled by using a generic integration technology

Photonic integrated circuits for data read-out systems

We propose and design two photonic integrated circuits which can be used in a data read-out system. The designs are developed for use in a neutrino detector but the principle is applicable to a wider range of read-out systems. The first one is an optical serializer integrated with electro-optical modulators and semiconductor optical amplifiers and operates at a single wavelength. The second one employs a wavelength-division-multiplexing scheme and utilizes arrayed waveguide gratings, electro-optical modulators and semiconductor optical amplifiers

Compact polymer components for an integrated add-drop multiplexer

A phasar and a digital thermo optic switch have been designed and processed in a high index contrast polymer technology. Both devices are small enough to fabricate two integrated add-drop multiplexers on one 4 inch wafe

Integrated multi-wavelength lasers : a design study

Multi-wavelength lasers (MWLs) play an important role in wavelength division multiplexing networks, and also in photonic radar beam steering applications. In this paper we study different options for realizing such lasers, monolithically integrated with radio frequency (RF) modulators that can be modulated up to 40 GHz. Configurations of arrayed waveguide grating (AWG)-based MWLs integrated with Mach-Zehnder modulators are discussed. Depending on the application, they can have spatially separated modulated outputs or the modulated signals can be multiplexed onto a common output. A novel configuration, that exploits the reflection and transmission properties of on-chip reflectors is presented.

Characterization of integrated electro-optically tunable cascaded filters for tunable laser purposes

In this contribution we present our results on the tunable arrayed waveguide gratings designed and fabricated to be used in a tunable ring laser structure in the 1600 to 1800nm range. To be able to tune the two cascaded filters over 100 to 200nm the wavelength dependent phase shifting in the phase shifters have been measured. With the knowledge of the wavelength dependency in the phase shifters we are able to tune the AWG over the full wavelength range

Qualification and Flight of a Cutting Edge Sunsensor for Constellation Applications

Satellites for a constellation can be build in a significantly more cost-effective way because the Non-recurring Engineering charges (NRE) can be spread over multiple units. A further significant cost reduction can be achieved if the units and subsystems are optimized for volume production and the units are produced in a continuous production line with a sustainable throughput. Though this optimized production can lead to significant improvement in cost effectiveness, this should in no way impair the reliability of the products. It can be reasoned that the approach implemented by Lens R&D will even increase the reliability of production as it allows for statistical process monitor and control of the product quality. As reliability and cost effectiveness in volume production are core to the Return On Investment (ROI) for constellation owners, these properties have been core design drivers for the BiSon Sunsensors discussed in this paper. After a design change that led to the development of an automated assembly robot, the cutting edge BiSon64-ET and BiSon64-ET-B Sunsensors developed by Lens R&D went through a full ESA qualification program. This means that for the first time ever, a Sunsensor optimized for volume manufacturing has finished a full ESA qualification program. A flight contract has been signed to fly 20 sensors on the two ESA science satellites making up the Proba-3mission. Flight data however already will be received earlier, through a precursor 3U Cubesat mission, flown through the Dutch company Innovative Solutions In Space (ISIS). This paper focusses on the novel manufacturing approach used, the qualification performed and the processes needed to cost effectively produce large quantities of Sunsensors for constellation applications

A model for the operation of perovskite based hybrid solar cells:formation, analysis and comparison to experiment

This work is concerned with the modeling of perovskite based hybrid solar cells formed by sandwiching a slab of organic lead halide perovskite (CH3NH3PbI3?xClx) photo-absorber between (n-type) acceptor and (p-type) donor materials—typically titanium dioxide and spiro. A model for the electrical behavior of these cells is formulated based on drift-diffusion equations for the motion of the charge carriers and Poisson’s equation for the electric potential. It is closed by (i) internal interface conditions accounting for charge recombination/generation and jumps in charge carrier densities arising from differences in the electron affinity/ionization potential between the materials and (ii) ohmic boundary conditions on the contacts. The model is analyzed by using a combination of asymptotic and numerical techniques. This leads to an approximate—yet highly accurate—expression for the current-voltage relationship as a function of the solar induced photo- current. In addition, we show that this approximate current-voltage relation can be interpreted as an equivalent circuit model consisting of three diodes, a resistor, and a current source. For sufficiently small biases the device’s behavior is diodic and the current is limited by the recombination at the internal interfaces, whereas for sufficiently large biases the device acts like a resistor and the current is dictated by the ohmic dissipation in the acceptor and donor. The results of the model are also compared to experimental current-voltage curves, and good agreement is shown

Reversal of Hartmann's procedure after perforated diverticulitis through the stomal side without additional incisions: The SIR procedure

Aims: Reversal of Hartmann's procedure (HP) is a complex operation and only performed in 50-60% of the patients. Stomal incision reversal (SIR), a new minimally invasive procedure for HP reversal, was assessed and compared to the standard surgical approach. Methods: 16 patients who had undergone HP for perforated diverticulitis underwent HP reversal by SIR. The only incision in SIR is the one to release the end colostomy. Intra-abdominal adhesiolysis is done manually. A stapled end-to-end colorectal anastomosis is created. The 16 patients who underwent SIR were compared with 32 control patients who were matched according to gender, age, American Society of Anesthesiologists (ASA) classification and Hinchey stage. Results: The operation time was shorter after SIR than after reversal by laparotomy [75 min (58-208) vs. 141 min (85-276); p < 0.001]. Patients after SIR had a shorter hospital stay than patients after laparotomy [4 days (2-22) vs. 9 days (4-64); p < 0.001]. The numbers of total postoperative surgical complications (early and late) were not different (p = 0.13). The anastomotic leakage rate was similar in both groups (6%). The conversion rate in the SIR group was 19% (n = 3). Conclusion: SIR compared favorably with HP reversal by laparotomy in terms of operation time and hospital stay, without increasing the number of postoperative complications. Copyrigh