Blar i USN Open Archive på forfatter "Karlsen, Bjørnar"
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Bipolar photodiode module operated at 4 K
Bardalen, Eivind; Nissilä, Jaani; Fordell, Thomas; Karlsen, Bjørnar; Kieler, Oliver; Øhlckers, Per (Chapter, 2020)An optoelectronic module for generating high frequency bipolar current pulses at 4 K was developed. Bipolar signals are generated by connecting a pair of photodiodes in series to coplanar waveguides on silicon. The ... -
Characterization of high-precision resistive voltage divider and buffer amplifier for ac voltage metrology
Karlsen, Bjørnar; Lind, Kåre; Malmbekk, Helge; Øhlckers, Per (Peer reviewed; Journal article, 2019)A high-precision voltage buffer and a 10:1 resistive voltage divider have been constructed for use in ac voltage and electrical power metrology. Long-term stability of the buffer's dc response has been demonstrated by two ... -
Driving a low critical current Josephson junction array with a mode-locked laser
Nissilä, J.; Fordell, Thomas; Kohopää, K.; Mykkänen, E.; Immonen, P.; Jabdaraghi, R. N.; Bardalen, Eivind; Kieler, Oliver; Karlsen, Bjørnar; Øhlckers, Per; Behr, Ralf; Manninen, A. J.; Govenius, J.; Kemppinen, A. (Peer reviewed; Journal article, 2021)We report proof-of-concept experiments on an optically driven Josephson voltage standard based on a mode-locked laser (MLL), a time-division multiplexer, and a cryogenic ultrafast photodiode driving an overdamped Josephson ... -
High-Speed Pulsation of a Cryogenically Operable Bipolar Photodiode Module for the Josephson Arbitrary Waveform Synthesizer
Karlsen, Bjørnar; Bardalen, Eivind; Nissilä, Jaani; Fordell, Thomas; Kieler, Oliver; Palafox, Luis; Behr, Ralf; Malmbekk, Helge; Akram, Muhammad Nadeem; Øhlckers, Per (Peer reviewed; Journal article, 2020)This paper describes the development and testing of a prototype of a cryogenically operable bipolar photodiode module. Optical pulsation systems based on both a Mach-Zehnder modulator and a mode-locked laser have been used ... -
Optically operated pulse-driven Josephson junction arrays and range extension using voltage dividers and buffer amplifiers
Karlsen, Bjørnar (Doctoral dissertations at the University of South-Eastern Norway;52, Doctoral thesis, 2019)Voltage dividers and buffer amplifier combinations can be used to transfer and extend traceability in voltage and electrical power metrology between a wide range of instruments. For voltages up to 1000 V, resistive voltage ...