S. Hunziker
A5044023288- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Solar and Space Plasma Dynamics
- Stellar, planetary, and galactic studies
- Semiconductor Lasers and Optical Devices
- Photonic and Optical Devices
- Planetary Science and Exploration
- Particle Accelerators and Free-Electron Lasers
- Laser Design and Applications
- Semiconductor Quantum Structures and Devices
- Optical Network Technologies
- Advanced Fiber Laser Technologies
- Advanced X-ray Imaging Techniques
- Astronomy and Astrophysical Research
- Calibration and Measurement Techniques
- Adaptive optics and wavefront sensing
- Advanced Photonic Communication Systems
- Particle accelerators and beam dynamics
- Space Science and Extraterrestrial Life
- Galaxies: Formation, Evolution, Phenomena
- Geomagnetism and Paleomagnetism Studies
- Astronomical Observations and Instrumentation
- solar cell performance optimization
- Dark Matter and Cosmic Phenomena
- Ionosphere and magnetosphere dynamics
ETH Zurich
1998-2023
Paul Scherrer Institute
2016-2017
École Polytechnique Fédérale de Lausanne
1996-1997
Context . The SPHERE “planet finder” is an extreme adaptive optics (AO) instrument for high resolution and contrast observations at the Very Large Telescope (VLT). We describe Zurich Imaging Polarimeter (ZIMPOL), visual focal plane subsystem of SPHERE, which pushes limits current AO systems to shorter wavelengths, higher spatial resolution, much improved polarimetric performance. Aims present a detailed characterization SPHERE/ZIMPOL should be useful optimal planning improving data reduction...
Aims: We want to detect and quantify observables related accretion processes occurring locally in circumstellar disks, which could be attributed young forming planets. focus on objects known host protoplanet candidates and/or disk structures thought the result of interactions with Methods: analyzed observations 6 stars (age $3.5-10$ Myr) their surrounding environments SPHERE/ZIMPOL instrument VLT H$\alpha$ filter (656 nm) a nearby continuum (644.9 nm). Results: re-detect accreting M-star...
The SwissFEL Injector Test Facility operated at the Paul Scherrer Institute between 2010 and 2014, serving as a pilot plant testbed for development realization of SwissFEL, X-ray Free-Electron Laser facility under construction same institute. test consisted laser-driven rf electron gun followed by an S-band booster linac, magnetic bunch compression chicane diagnostic section including transverse deflecting cavity. It delivered bunches up to 200 pC charge 250 MeV beam energy repetition rate...
We present high-precision photometry and polarimetry for the protoplanetary disk around HD142527, with a focus on determining light scattering parameters of dust. re-reduced polarimetric differential imaging data HD142527 in VBB (735 nm) H-band (1625 from ZIMPOL IRDIS subinstruments SPHERE/VLT. With based reference star imaging, we were able to measure linearly polarized intensity total scattered by circumstellar high precision. used simple Monte Carlo simulations multiple surface derive...
We present the multiple stellar systems observed within SpHere INfrared survey for Exoplanet (SHINE). SHINE searched sub-stellar companions to young stars using high contrast imaging. Although with known SPHERE field of view (< 5.5 arcsec) were removed from original target list, we detected additional 78 463 targets so far. Twenty-seven per cent have three or more components. Given heterogeneity sample in terms observing conditions and strategy, tailored routines used data reduction...
Due to the relative motion of solar system through its local interstellar environment, dust can enter heliosphere. The trajectories are influenced by gravitational forces, radiation pressure force and wind Lorentz on charged grains. Finally, these micro-particles be measured in situ cosmic instruments.&#160;One most extensive databases stems from Ulysses detector. However, distinguishing interplanetary is a major challenge selection criteria may influence conclusions made based...
Abstract The Venetia Burney Student Dust Counter (SDC) is an in situ dust detector on board the New Horizons spacecraft measuring interplanetary particle (IDP) distribution for grains with mass m > 10 −12 g. SDC provides a near-continuous measure of environment, recent results spanning beyond 50 au. This coverage includes Edgeworth–Kuiper Belt (EKB), suggested by numerical models to be dominant source IDP outer solar system. Here we present updated density au and compare estimated flux...
Ground-based observations at thermal infrared wavelengths suffer from large background radiation due to the sky, telescope and warm surfaces in instrument. This significantly limits sensitivity of ground-based longer than 3 microns. We analyzed this emission high contrast imaging data, show how it can be modelled subtracted demonstrate that improve detection faint sources, such as exoplanets. applied principal component analysis model subtract three archival angular differential datasets M L...
RefPlanets is a guaranteed time observation (GTO) programme that uses the Zurich IMaging POLarimeter (ZIMPOL) of SPHERE/VLT for blind search exoplanets in wavelengths from 600-900 nm. The goals this study are characterization unprecedented high polarimetic contrast and polarimetric precision capabilities ZIMPOL bright targets, polarized reflected light around some closest stars to Sun potentially direct detection an evolved cold exoplanet first time. For our observations Alpha Cen A B,...
An 850 nm single transverse mode vertical-cavity surface-emitting laser (VCSEL) pigtailed to a standard 1300 nm-optimised 9/125 µm singlemode fibre (SMF) is presented as low-cost light source for radio over transmission. The spurious-free dynamic range of link using such VCSEL pigtail found be above 90 dBHz2/3 up 2 km SMF, thus fulfilling the requirements mobile communication systems.
We performed observations of the Sco-Cen F star HD 117214 aiming at a search for planetary companions and characterization debris disk structure. was observed with SPHERE subsystems IRDIS, IFS ZIMPOL optical near-IR wavelengths using angular polarimetric differential imaging techniques. This provided first images scattered light from spatial resolution reaching 25 mas an inner working angle $< 0.1''$. With IRDIS we derive detection limits substellar companions. The geometrical parameters...
Context. Cold planets, including all habitable produce only scattered light emission in the visual to near-infrared wavelength range. For this reason it is highly desirable adapt technique for direct imaging of reflected from extra-solar planets. Aims. nearby system ε Eri, we want set much deeper detection limits expected radiation radial velocity planet candidate (≈0.7 M J ) and warm dust using VLT/SPHERE adaptive optics (AO) instrument with ZIMPOL polarimeter. Methods. We carried out very...
Remote antennas in cellular telephone networks can be supplied by coaxial cable or optical fibre. It is useful to know which of the two technologies more appropriate with respect dynamic range and costs. Coaxial fibre links are considered for GSM applications. The link length-dependent costs compared reasonable values range.
Impact ionization of high-velocity cosmic dust particles has been used as a basic principle for detectors in space many decades. It provided optimum means to gain insight into the environment solar system. The Ulysses Dust Detector System first time impact ionization-based detection interstellar (ISD) system and discovered surprisingly heavy ISD with sizes up few microns. Studies based on astronomical observations local medium, other hand, suggested much smaller upper limit around 0.25 μm...
Sirius-like systems are wide binaries composed of a white dwarf (WD) and companion spectral type earlier than M0. The WD progenitor evolves in isolation, but its wind during the AGB phase pollutes surface transfers some angular momentum. Within SHINE survey that uses SPHERE at VLT, we acquired images HD2133, HD114174, CD-567708 combined this data with high resolution spectra primaries, TESS, literature data. We performed accurate abundance analyses for MS. found brighter J K magnitudes...
A low-cost adaptive predistortion circuit to reduce 3rd order intermodulation of semiconductor lasers has been designed. Using a microcontroller adjust the control voltages reduced by 20 dB over frequency range 1750 1870 MHz.
In modern low cost RF amplifiers or fibre optic links, it is essential to know the limit of third order intercept point definition make accurate intermodulation predictions. The authors present a simple formula calculate this from data sheet parameters' and 1dB compression point.
Summary form only given. Top and bottom emitting 1D 2D VCSEL arrays offer new perspectives in optical electrical packaging are therefore of high interest for future short haul parallel links, board-to-board on-board high-speed interconnects. Results short-wavelength multi-transverse mode demonstrating excellent uniformity, low threshold current, modulation efficiency multi-gigabit performance presented.
Abstract SwissFEL is a compact, high-brilliance, soft and hard X-ray free electron laser (FEL) facility that started user operation in 2019. The composed of two parallel beam lines seeded by common linear accelerator (LINAC), two-bunch photo-injector. For the injector, an innovative dual-photocathode scheme has been developed based on state-of-the-art ytterbium femtosecond systems. In this paper, we describe performance photocathode drive lasers (PCDLs), pulse-shaping capabilities as well...