Ola Gunnarsson

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Experimental studies of superconductivity properties of fullerides are briefly reviewed. Theoretical calculations of the electron-phonon coupling, in particular for the intramolecular phonons, are discussed extensively. The calculations are compared with coupling constants deduced from a number of different experimental techniques. It is discussed why the(More)
The concept of direct microwave optical filtering is introduced. A microwave signal is transferred into the optical domain and processed by means of optical wavelength selective elements. A tunable quasi-passband direct microwave optical filter employing fibre Bragg gratings working in transmission is demonstrated experimentally. The aspects of stability(More)
A fiber-optic system for continuous high sampling rate measurement of strain is presented in this paper. It is clear that many applications require a monitoring system with high sampling rate capability and the ability to multiplex many sensors. This has led to the definition and development of a time-domain multiplexed system for measurement of strain and(More)
A Josephson potentiometer method has been developed at SP for Quantum Hall Resistance (QHR) measurements. The QHR 12.9 k/spl Omega/ value is used for the determination of the resistance value of a room temperature 10 k/spl Omega/ resistor. The measurements have given excellent agreement with the maintained 1 /spl Omega/ primary group level.
The Euromet.EM-S18 resistance comparison have been carried out between Danish Fundamental Metrology (DFM), Swedish National Testing and Research Institute (SP), Centre for Metrology and Accreditation in Finland (MIKES) and Justervesenet (JV) from May to November 2003. This was a comparison of the calibration of 1 Ω and 10 kΩ resistors(More)
A compact mass-production ready 18-tap microwave photonic filter based on fiber Bragg gratings which slice a light source spectrum is presented. The operation frequency, 3-dB bandwidth, sidelobe suppression, and total length of the filter are 10 GHz, 0.8 GHz, 40 dB, and 17.9 cm, respectively. The fiber Bragg gratings comprising the filter are fabricated(More)
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