Publications de Iwan Märki | EPFL Graph Search

Triplet imaging of oxygen consumption during the contraction of a single smooth muscle cell (A7r5)

Theo Lasser, Dimitri Nestor Alice Van De Ville, Kai Johnsson, Marcel Leutenegger, Boris Hinz, Iwan Märki, Thiemo Spielmann, Aurélie Formey de Saint Louvent, Matthias Geissbühler

Triplet imaging is a novel optical technique that allows investigating oxy- gen metabolism at the single cell and the sub-cellular level. The method combines high temporal and spatial resolution, which are required for the monitoring of fast kinetics of ox ...

Springer Science+Business Media2012

Nonlinear Correlation Spectroscopy (NLCS)

Theo Lasser, Marcel Leutenegger, Iwan Märki, Jean-Pierre Wolf, Noelia Laura Bocchio, Luigi Bonacina, Stefan Geissbuehler

We present a novel concept for optical spectroscopy called nonlinear correlation spectroscopy (NLCS). NLCS analyses coherent field fluctuations of the second and third harmonic light generated by diffusing nanoparticles. Particles based on noncentrosymmetr ...

American Chemical Society2012

Functional optical coherent imaging platform for medical application e.g. neurosurgery, has active camera unit that captures image of specific region of test subject after transmitting stimulus signals

Theo Lasser, Dimitri Nestor Alice Van De Ville, Marcel Leutenegger, Martin Villiger, Iwan Märki, Erica Martin-Williams, Michael Friedrich

The present invention relates to a functional optical coherent imaging (fOCI) platform comprising at least one active camera unit (ACU) comprising a coherent and/or a partially coherent light source, and means for spectral filtering and imaging a selected ...

2010

Targeted Photoswitchable Probe for Nanoscopy of Biological Structures

Theo Lasser, Kai Johnsson, Iwan Märki, Stefan Geissbühler, Noelia Laura Bocchio, Grazvydas Lukinavicius, Claudio Dellagiacoma, Sambashiva Banala

We introduce a photoswitchable O6-benzylguanine derivative and demonstrate its use for super-resolution microscopy of SNAP-tagged proteins based on single fluorophore localization. Stochastic Optical Reconstruction Microscopy (STORM) reveals SNAP-tagged mi ...

2010

Three-dimensional nano-localization of single fluorescent emitters

Theo Lasser, Iwan Märki, François Aguet, Stefan Geissbühler, Noelia Laura Bocchio

We present a combination of self-interference microscopy with lateral super-resolution microscopy and introduce a novel approach for localizing a single nano-emitter to within a few nanometers in all three dimensions over a large axial range. We demonstrat ...

Optical Society of America2010

Super-resolved position and orientation estimation of fluorescent dipoles using 3-D steerable filters

Theo Lasser, Iwan Märki, François Aguet, Stefan Geissbühler

The diffraction patterns of fixed fluorophores are characteristic of the orientation of the molecules' underlying dipole. Fluorescence localization microscopy techniques such as PALM and STORM achieve super-resolution by sequentially imaging sparse subsets ...

Spie-Int Soc Optical Engineering, Po Box 10, Bellingham, Wa 98227-0010 Usa2010

Steerable filters for orientation estimation and localization of fluorescent dipoles

Michaël Unser, Theo Lasser, Iwan Märki, Stefan Geissbühler, François Aguet

Fluorescence localization microscopy (i.e., PALM, STORM) has enabled optical imaging at nanometer-scale resolutions. The localization algorithms used in these techniques rely on fitting a 2-D Gaussian to the in-focus image of individual fluorophores. For f ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2009

High volume confinement in two-photon total-internal- reflection fluorescence correlation spectroscopy

Theo Lasser, Marcel Leutenegger, Iwan Märki, Denis Ivanov

We report results on two-photon total-internal-reflection fluorescence correlation spectroscopy with radially polarized light. The combination of liquid crystal spatial light modulator, providing radial polarization, with ultrafast laser (picosecond Nd:GdV ...

AIP American Institute of Physics2009

Super-resolution orientation estimation and localization of fluorescent dipoles using 3-D steerable filters

Michaël Unser, Theo Lasser, Iwan Märki, François Aguet, Stefan Geissbühler

Fluorophores that are fixed during image acquisition produce a diffraction pattern that is characteristic of the orientation of the fluorophore’s underlying dipole. Fluorescence localization microscopy techniques such as PALM and STORM achieve super-resolu ...

OSA2009

Tuning the resonance of a photonic crystal microcavity with an AFM probe

Iwan Märki, Hans Peter Herzig

We present theoretical and experimental results on switching and tuning of a two-dimensional photonic crystal resonant microcavity by means of a silicon AFM tip, probing the highly localized optical field in the vicinity of the cavity. On-off switching and ...

2006