Submicron active-passive integration for InP-based membranes on silicon

The high vertical index contrast and the small thickness of thin InP-based membrane structures bonded with BCB on Silicon allow the realization of very small devices. To make photonic integrated circuits with both passive and active components in these membranes, active-passive integration on a small scale is essential. In this paper we will present our results on sub-micrometer active areas for membrane applications

Observations of microquasars with the MAGIC telescope

We report on the results from the observations in very high energy band (VHE, E_gamma > 100GeV) of the black hole X-ray binary (BHXB) Cygnus X-1. The observations were performed with the MAGIC telescope, for a total of 40 hours during 26 nights, spanning the period between June and November 2006. We report on the results of the searches for steady and variable gamma-ray signals, including the first experimental evidence for an intense flare, of duration between 1.5 and 24 hours.Comment: Contribution to the 30th ICRC, Merida Mexico, July 2007 on behalf of the MAGIC Collaboratio

Oxidation of AlInAs for current blocking in a photonic crystal laser

To make an electrically pumped photonic crystal membrane laser is a challenging task. One of the problems is how to avoid short circuiting between the p- and n-doped parts of the laser diode, when the membrane thickness is limited to 200-300nm. We propose to use the oxide of AlInAs to realize a current blocking function. In this way, based on submicron selective area re-growth, we aim for electrically injected photonic crystal lasers with high output power, small threshold currents and low power consumption. Here results are presented on the oxidation of AlInAs. The results show that it is feasible to use the oxide of AlInAs for current blocking in an InP-based membrane photonic crystal laser

Investigation of the chemical vapor deposition of Cu from copper amidinate through data driven efficient CFD modelling

peer reviewedA chemical reaction model, consisting of two gas-phase and a surface reaction, for the deposition of copper from copper amidinate is investigated, by comparing results of an efficient, reduced order CFD model with experiments. The film deposition rate over a wide range of temperatures, 473K-623K, is accurately captured, focusing specifically on the reported drop of the deposition rate at higher temperatures, i.e above 553K that has not been widely explored in the literature. This investigation is facilitated by an efficient computational tool that merges equation-based analysis with data-driven reduced order modeling and artificial neural networks. The hybrid computer-aided approach is necessary in order to address, in a reasonable time-frame, the complex chemical and physical phenomena developed in a three-dimensional geometry that corresponds to the experimental set-up. It is through this comparison between the experiments and the derived simulation results, enabled by machine-learning algorithms that the prevalent theoretical hypothesis is tested and validated, illuminating the possible underlying dominant phenomena

Microlasers based on effective index confined slow light modes in photonic crystal waveguides

We present the design, theory and experimental implementation of a low modal volume microlaser based on a line-defect 2D-photonic crystal waveguide. The lateral confinement of low-group velocity modes is controlled by the post-processing of 1 to 3μm wide PMMA strips on top of two dimensional photonic crystal waveguides. Modal volume around 1.3 (λ/n)3can be achieved using this scheme. We use this concept to fabricate microlaser devices from an InP-based heterostructure including InAs0.65P0.35quantum wells emitting around 1550nm and bonded onto a fused silica wafer. We observe stable, room-temperature laser operation with an effective lasing threshold around 0.5mW. © 2008 Optical Society of America

Demonstration of coherent emission from high-β\beta photonic crystal nanolasers at room temperature

We report on lasing at room temperature and at telecommunications wavelength from photonic crystal nanocavities based on InAsP/InP quantum dots. Such laser cavities with a small modal volume and high quality factor display a high spontaneous emission coupling factor beta. Lasing is confirmed by measuring the second order autocorrelation function. A smooth transition from chaotic to coherent emission is observed, and coherent emission is obtained at 8 times the threshold power

Bullying in Primary and Secondary school in the view of University Students

Bullying is one of the most serious problems that education has, and one of the most serious problems of the educational system in this day and age. It affects almost all students, with them either being a bully, a victim of bullying, or a bystander. But it also has an important effect on the teaching staff, the schools themselves, and the educational system. For this research, we asked first- and second-year university students about their perception of bullying in their stages as students of primary and secondary education. To do this, we evaluated 654 university students: 195 men (29.82%) and 459 women (70.18%). These students were from eight different departments at the University of Zaragoza. The age of the participants ranged from 18 to 27 years, with an average of 22.54 years (s.d. = .292). The results showed that men tend to be bullies to a greater extent than women, and no relationship was found between gender and being a victim of bullying. In addition, it was found that nearly two out of every three students have experienced bullying during these stages of education and that almost all students (nine out of ten) have seen episodes of bullying. As a conclusion, we must point out the need for further studies and research work to discuss and analyze the phenomenon of bullying – a phenomenon that affects both students and our educational system