1,471 research outputs found
Self Phase Modulation and Stimulated Raman Scattering due to High Power Femtosecond Pulse Propagation in Silicon-on-Insulator Waveguides.
Self Phase Modulation (SPM) and Stimulated Raman Scattering (SRS) in silicon waveguides have been observed and will be discussed theoretically using a modified Nonlinear Schrödinger Equation. The high optical peak powers needed for the experiments were obtained by coupling sub-picosecond (200fs) transform limited pulses with a spectral width of 12nm into a single mode silicon waveguide. Spectral broadening up to 50nm has been observed due to Self Phase Modulation. An intensity increase of the idler spectrum around 1650nm at the expense of the 1550nm pump signal has been observed as function of pump power, indicating the presence of Stimulated Raman Scattering
Uniform non-stoichiometric titanium nitride thin films for improved kinetic inductance detector array
We describe the fabrication of homogeneous sub-stoichiometric titanium
nitride films for microwave kinetic inductance detector (mKID) arrays. Using a
6 inch sputtering target and a homogeneous nitrogen inlet, the variation of the
critical temperature over a 2 inch wafer was reduced to <25 %. Measurements of
a 132-pixel mKID array from these films reveal a sensitivity of 16 kHz/pW in
the 100 GHz band, comparable to the best aluminium mKIDs. We measured a noise
equivalent power of NEP = 3.6e-15 W/Hz^(1/2). Finally, we describe possible
routes to further improve the performance of these TiN mKID arrays.Comment: 7 pages, 4 figures, submitted to Journal of low temperature physics,
Proceedings of LTD-1
Design and characterization of SiON integrated optics components for optical coherence tomography
Optical coherence tomography (OCT) is a technique for high resolution imaging of biological tissues with a depth range of a few millimeters. OCT is based on interferometry to enable depth ranging. Currently, optical components for OCT are rather bulky and expensive; the use of integrated optical circuits presents a great opportunity to reduce costs and enhance system functionality and performance. We present the design and characterization of SiON-based integrated optics waveguides, splitters, couplers and interferometers for OCT operating at a wavelength of 1.3 um
Anomalous response of superconducting titanium nitride resonators to terahertz radiation
We present an experimental study of KIDs fabricated of atomic layer deposited
TiN films, and characterized at radiation frequencies of ~GHz. The
responsivity to radiation is measured and found to increase with increasing
radiation powers, opposite to what is expected from theory and observed for
hybrid niobium titanium nitride / aluminium (NbTiN/Al) and all-aluminium
(all-Al) KIDs. The noise is found to be independent of the level of the
radiation power. The noise equivalent power (NEP) improves with higher
radiation powers, also opposite to what is observed and well understood for
hybrid NbTiN/Al and all-Al KIDs. We suggest that an inhomogeneous state of
these disordered superconductors should be used to explain these observations
Integrated AWG spectrometer for on-chip optical coherence tomography and Raman spectroscopy
Silicon oxynitride-based arrayed waveguide grating (AWG) spectrometers were designed for on-chip spectral-domain optical coherence tomography (OCT) systems and Raman spectroscopy of the skin. A novel geometrical layout for Raman spectroscopy was introduced to reduce loss. Measurements show that integrated optics has a good potential for miniaturizing current OCT systems
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