Blar i NTNU Open på forfatter "Engan, Helge Emil"
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Acoustooptic characterization of a birefringent two-mode photonic crystal fiber
Haakestad, Magnus Willum; Engan, Helge Emil (Journal article; Peer reviewed, 2006)The effect of axial variations in acoustooptic phase-mismatch coefficient of a two-mode birefringent photonic crystal fiber (PCF) is studied experimentally using two different methods. The first method is to determine axial ... -
Heterodyne interferometer for absolute amplitude vibration measurements with femtometer sensitivity
Leirset, Erlend; Engan, Helge Emil; Aksnes, Astrid (Journal article; Peer reviewed, 2013)A heterodyne interferometer for highly sensitive vibration measurements in the range 100kHz − 1.3GHz is presented. The interferometer measures absolute amplitude and phase. The signal processing of the setup is analyzed ... -
Wide frequency range measurements of absolute phase and amplitude of vibrations in micro- and nanostructures by optical interferometry
Martinussen, Hanne; Aksnes, Astrid; Engan, Helge Emil (Journal article; Peer reviewed, 2007)A heterodyne interferometer has been built in order to characterize vibrations on micro- and nanostructures. The interferometer offers the possibility of both absolute phase and high resolution absolute amplitude vibrational ...