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Rodriguez J.G.,Technical University of Madrid | Iriarte G.F.,Technical University of Madrid | Calle F.,Technical University of Madrid | Araujo D.,University of Cadiz | And 2 more authors.
Proceedings of the 8th Spanish Conference on Electron Devices, CDE'2011 | Year: 2011

The AlN/diamond structure is an attractive combination for SAW devices and its application at high frequencies. In this work, the synthesis of AlN thin films by reactive sputtering has been optimized on diamond substrates in order to process high frequency devices. Polished microcrystalline and as-grown nanocrystalline diamond substrates have been used to deposit AlN of different thickness under equal sputtering conditions. For the smoother substrates, the FWHM of the rocking curve of the (002) AlN peak varies from 3.8 to 2.7 with increasing power. SAW one port resonators have been fabricated on these films, whose electrical characterization (in terms of S11 parameters) is reported. © 2011 IEEE.

Michaelson S.,Technion - Israel Institute of Technology | Stacey A.,University of Melbourne | Orwa J.,University of Melbourne | Cimmino A.,University of Melbourne | And 5 more authors.
Journal of Applied Physics | Year: 2010

The thermal stability of nanocrystalline diamond films with 10-30 nm grain size deposited by microwave enhanced chemical vapor deposition on silicon substrate was investigated as a function of annealing temperature up to 1200°C. The thermal stability of the surface-upper atomic layers was studied with near edge x-ray absorption fine structure (NEXAFS) spectroscopy recorded in the partial electron yield mode. This technique indicated substantial thermally induced graphitization of the film within a close proximity to the surface. While in the bulk region of the film no graphitization was observed with either Raman spectroscopy or NEXAFS spectroscopy recorded in total electron yield mode, even after annealing to 1200°C. Raman spectroscopy did detect the complete disappearance of transpolyacetylene (t-PA)-like 1 and 3 modes following annealing at 1000°C. Secondary ion mass spectroscopy, applied to investigate this relative decrease in hydrogen atom concentration detected only a ∼30% decrease in the bulk content of hydrogen atoms. This enhanced stability of sp3 hybridized atoms within the bulk region with respect to graphitization is discussed in terms of carbon bond rearrangement due to the thermal decomposition of t-PA-like fragments. © 2010 American Institute of Physics.

Pierscinski K.,Polish Institute of Electron Technology | Pierscinska D.,Polish Institute of Electron Technology | Bugajski M.,Polish Institute of Electron Technology | Manz C.,Institute For Angewandte Festkorperphysik | Rattunde M.,Institute For Angewandte Festkorperphysik
Journal of Applied Physics | Year: 2012

The thermal behavior of vertical-external-cavity-surface-emitting lasers (VECSELs) is investigated. The temperature distribution in operating VECSELs has been experimentally determined for various operating conditions and different cooling schemes. The implementation of the thermoreflectance technique for the thermal analysis of VECSELs is demonstrated. This technique allows for high resolution mapping of a temperature increase resulting from the optical pumping of the VECSEL. The influence of a heatspreader on the VECSEL temperature is investigated. It is demonstrated that the use of an intracavity heatspreader bonded to the VECSEL chip causes a pronounced decrease of the temperature of the device. From the heat balance in the device, the lowering of the temperature of the VECSEL during operation is predicted. This is experimentally confirmed. © 2012 American Institute of Physics.

Derksen R.H.,Coriant | Westergren U.,KTH Royal Institute of Technology | Chacinski M.,KTH Royal Institute of Technology | Schubert C.,Heinrich Hertz Institute | And 6 more authors.
IEEE Communications Magazine | Year: 2013

In 2010, the standard for 100GbE was approved, which specifies the transmission of 100 Gb/s via 4 wavelength channels of 25 Gb/s each. A solution based on a 100 Gb/s single wavelength channel is capable of significant cost reductions should the required components be available. Within the HECTO project, we developed components suitable for single-wavelength 100 Gb/s transmission. In this article, the project is described-its organization, objectives, possible impacts, and results-including the successful demonstration in a final field trial. A complete ETDM system utilizing the monolithically integrated transmitter and receiver modules developed in the project was built to transmit 112 Gb/s over 42 km standard single-mode fiber. Finally, we attempt an outlook on the prospective development of Ethernet standardization beyond 100GbE. © 2013 IEEE.

Pierscinski K.,Polish Institute of Electron Technology | Pierscinska D.,Polish Institute of Electron Technology | Bugajski M.,Polish Institute of Electron Technology | Manz C.,Institute For Angewandte Festkorperphysik | Rattunde M.,Institute For Angewandte Festkorperphysik
Proceedings of SPIE - The International Society for Optical Engineering | Year: 2010

In this paper the investigation of thermal properties of the optically pumped vertical external cavity surface emitting lasers (VECSEL) is reported. The experimental technique used is thermoreflectance. The original achievements of the paper include design and construction of experimental setups allowing the measurement of the temperature distributions on the surface of the operating VECSEL with and without heatspreader. The temperature increase in case of the VECSEL with SiC heatspreader is reduced by the factor of almost 10 in comparison to the VECSEL without the heatspreader. Additionally, the lowering of the temperature of lasing VECSEL was observed experimentally. © 2010 SPIE.

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