A5057385856- Orbital Angular Momentum in Optics
- Random lasers and scattering media
- Optical Coherence Tomography Applications
- Near-Field Optical Microscopy
- Microfluidic and Bio-sensing Technologies
- Advanced Fluorescence Microscopy Techniques
- Digital Holography and Microscopy
- Photonic Crystal and Fiber Optics
- Spectroscopy Techniques in Biomedical and Chemical Research
- Photoreceptor and optogenetics research
- Advanced Optical Imaging Technologies
- Cold Atom Physics and Bose-Einstein Condensates
- Laser Material Processing Techniques
- Laser-Matter Interactions and Applications
- Photoacoustic and Ultrasonic Imaging
- Advanced Fiber Laser Technologies
- Advanced Optical Sensing Technologies
- Photonic and Optical Devices
- Optical Network Technologies
- Plasmonic and Surface Plasmon Research
- Neural dynamics and brain function
- Neural Networks and Reservoir Computing
- Gold and Silver Nanoparticles Synthesis and Applications
- Electrohydrodynamics and Fluid Dynamics
- Optical Polarization and Ellipsometry
Czech Academy of Sciences, Institute of Scientific Instruments
2009-2024
Leibniz Institute of Photonic Technology
2017-2024
Friedrich Schiller University Jena
2020-2024
Czech Academy of Sciences
2006-2023
Maksymilian Pluta Institute of Applied Optics
2021-2023
University of Dundee
2014-2018
University of St Andrews
2008-2015
Masaryk University
2004-2006
There has been an immense drive in modern microscopy towards miniaturization and fibre-based technology. This necessitated by the need to access hostile or difficult environments situ vivo. Strategies date have included use of specialist fibres miniaturized scanning systems accompanied ingenious microfabricated lenses. Here we present a novel approach for this field utilizing disordered light within standard multimode optical fibre lensless mode conversion. We demonstrate modalities bright-...
We present a powerful approach towards full understanding of laser light propagation through multimode optical fibres and control the at fibre output.Transmission within introduces randomization beam amplitude, phase polarization.We discuss importance each these factors introduce an experimental geometry allowing analysis transmission subsequent beam-shaping using single spatial modulator.We show that this one can generate arbitrary output field accessible view range frequencies given by...
We study theoretically and experimentally the spatial intensity distribution of zero-order Bessel beam formed by axicon which possess a rounded tip. Such tip generates refracted that interferes with quasi-Bessel created behind axicon. In turn an undesired modulation occurs significantly disturbs unique properties beam--namely constant shape lateral slow variation on-axis along propagation. show how filtration in Fourier plane improves this removes modulation. use efficient numerical method...
The last decade has seen the development of a wide set tools, such as wavefront shaping, computational or fundamental methods, that allow to understand and control light propagation in complex medium, biological tissues multimode fibers. A vibrant diverse community is now working on this field, revolutionized prospect diffraction-limited imaging at depth tissues. This roadmap highlights several key aspects fast developing some challenges opportunities ahead.
Time-of-flight three-dimensional (3D) imaging has applications that range from industrial inspection to motion tracking. Depth is recovered by measuring the round-trip flight time of laser pulses, typically using collection optics several centimeters in diameter. We demonstrate near–video-rate 3D through multimode fibers with a total aperture hundred micrometers. implement aberration correction wavefront shaping synchronized pulsed source and scan scene at ~23,000 points per second. image...
Light transport in a highly multimode fiber exhibits complex behavior space, time, frequency and polarization, especially the presence of mode coupling. The newly developed techniques spatial wavefront shaping turn out to be suitable harness such enormous complexity: light modulator enables precise characterization field propagation through fiber, by adjusting incident it can accurately tailor transmitted pattern, temporal profile polarization state. This unprecedented control leads...
Abstract Light-based in-vivo brain imaging relies on light transport over large distances of highly scattering tissues. Scattering gradually reduces contrast and resolution, making it difficult to reach structures at greater depths even with the use multiphoton techniques. To deeper, minimally invasive endo-microscopy techniques have been established. These most commonly exploit graded-index rod lenses enable a variety modalities in head-fixed freely moving animals. A recently proposed...
We demonstrate an optical conveyor belt that provides trapping and subsequent precise delivery of several submicron particles over a distance hundreds micrometers. This tool is based on standing wave (SW) created from two counter-propagating nondiffracting beams where the phase one can be changed. Therefore, whole structure SW nodes antinodes moves delivering confined micro-objects to specific regions in space. Based theoretical calculations, we confirm experimentally certain sizes...
Due to their immunity diffraction, Bessel light modes potentially offer advantages in various applications. However, they do exhibit significant intensity variations along axial propagation length which hampers applicability. In this paper we present a technique generate beams with tunable within the accessible range of spatial frequencies. The beam may be engineered have constant its length. Finally, demonstrate how one can form varying extent results scaling lateral cross-section.
The impact of optical forces in the physical and biological sciences now enables manipulation objects ranging size from a cell down to single atom. mechanical effects fields have profound far-reaching consequences, attention is increasingly focused upon opportunities for non-contact assembly particles into specific geometries. present overview focuses on two aspects multi-particle trapping binding. These can broadly be grouped as methods based light-mediated inter-particle interactions,...
Abstract Achieving intravital optical imaging with diffraction-limited spatial resolution of deep-brain structures represents an important step toward the goal understanding mammalian central nervous system 1–4 . Advances in wavefront-shaping methods and computational power have recently allowed for a novel approach to high-resolution imaging, utilizing deterministic light propagation through optically complex media and, particular importance this work, multimode fibers (MMFs) 5–7 We report...
Progress in neuroscience constantly relies on the development of new techniques to investigate complex dynamics neuronal networks. An ongoing challenge is achieve minimally-invasive and high-resolution observations activity vivo inside deep brain areas. A perspective strategy utilise holographic control light propagation media, which allows converting a hair-thin multimode optical fibre into an ultra-narrow imaging tool. Compared current endoscopes based GRIN lenses or bundles, this concept...
We present a generic technique allowing size-based all-optical sorting of gold nanoparticles. Optical forces acting on metallic nanoparticles are substantially enhanced when they illuminated at wavelength near the plasmon resonance, as determined by particle's geometry. Exploiting these resonances, we realize in system two counter-propagating evanescent waves, each different wavelengths that selectively guide sizes opposite directions. validate this concept demonstrating bidirectional either...
Digital micro-mirror devices (DMDs) have recently emerged as practical spatial light modulators (SLMs) for applications in photonics, primarily due to their modulation rates, which exceed by several orders of magnitude those the already well-established nematic liquid crystal (LC)-based SLMs.This, however, comes at expense limited depth and diffraction efficiency.Here we compare beam-shaping fidelity both technologies when applied control complex environments, including an aberrated optical...
The dynamic spatial control of light fields is essential to a range applications, from microscopy optical micro-manipulation and communications. Here we describe the use single digital micro-mirror device (DMD) generate rapidly switch vector beams with spatially controllable intensity, phase polarisation. We demonstrate local over linear, elliptical circular polarisation, allowing generation radially azimuthally polarised Poincaré beams. All these can be switched at rates up 4kHz (limited...
Light transport through a multimode optical waveguide undergoes changes when subjected to bending deformations. We show that waveguides with perfectly parabolic refractive index profile are almost immune bending, conserving the structure of propagation-invariant modes. Moreover, we transmission matrix parabolic-index fibers due can be expressed only two free parameters, regardless how complex particular deformation is. provide detailed analysis experimentally measured matrices commercially...
Abstract The measurement of the optical transmission matrix (TM) an opaque material is advanced form space-variant aberration correction. Beyond imaging, TM-based methods are emerging in a range fields, including communications, micro-manipulation, and computing. In many cases, TM very sensitive to perturbations configuration scattering medium it represents. Therefore, applications often require up-to-the-minute characterisation fragile TM, typically entailing hundreds thousands probe...
Multimode fibres have recently been employed as high-resolution ultra-thin endoscopes, capable of imaging biological structures deep inside tissue in vivo. Here, we extend this technique to label-free non-linear microscopy with chemical contrast using coherent anti-Stokes Raman scattering (CARS) through a multimode fibre endoscope, which opens up new avenues for instant and in-situ diagnosis potentially malignant tissue. We use commercial 125 µm diameter, 0.29 NA GRIN fibre, wavefront...
Holographic wavefront manipulation enables converting hair-thin multimode optical fibres into minimally invasive lensless imaging instruments conveying much higher information densities than conventional endoscopes. Their most prominent applications focus on accessing delicate environments, including deep brain compartments, and recording micrometre-scale resolution images of structures in close proximity to the distal end instrument. Here, we introduce an alternative 'farfield' endoscope,...