Aleksandr Lanin - Academia.edu (original) (raw)
Papers by Aleksandr Lanin
Photonics, 2021
We demonstrate an adaptive wave-front shaping of optical beams transmitted through fiber bundles ... more We demonstrate an adaptive wave-front shaping of optical beams transmitted through fiber bundles as a powerful resource for multisite, high-resolution bioimaging. With the phases of all the beamlets delivered through up to 6000 different fibers within the fiber bundle controlled individually, by means of a high-definition spatial light modulator, the overall beam transmitted through the fiber bundle can be focused into a beam waist with a diameter less than 1 μm within a targeted area in a biotissue, providing a diffraction-limited spatial resolution adequate for single-cell or even subcellular bioimaging. The field intensity in the adaptively-focused continuous-wave laser beam in our fiber-bundle-imaging setting is more than two orders of magnitude higher than the intensity of the speckle background. Once robust beam focusing was achieved with a suitable phase profile across the input face of the fiber bundle, the beam focus can be scanned over a targeted area with no need for a fu...
Nonlinear microscopy techniques are widely used in the field of biophotonics thanks to their abil... more Nonlinear microscopy techniques are widely used in the field of biophotonics thanks to their ability to image in highly scattering tissues such as brain [1]. Techniques that use intrinsic sources of contrast rather than exogenous labels are of great interest, because they are suitable not only for fundamental biological research but also for clinical applications [2]. Neurons are the most studied cells in the central nervous system of mammals. However, in certain parts of brain glial cells called astrocytes outnumber neurons. Historically, astrocytes considered to be simple support cells that structure the brain and control blood brain barrier, but recently were discovered to have great functional diversity and play many roles in healthy tissues as well as in CNS disorders [3].
Optics Letters, 2019
Polarization maps of high-order harmonics are shown to enable a full vectorial characterization o... more Polarization maps of high-order harmonics are shown to enable a full vectorial characterization of petahertz electron currents generated in a crystalline solid by an ultrashort laser driver. As a powerful resource of this methodology, analysis of energy-momentum dispersion landscapes, defined by the electron band structure, can help identify, as our analysis shows, special directions within the Brillouin zone that can provide a preferable basis for polarization-sensitive high-harmonic mapping of anisotropic petahertz photocurrents in solids.
Journal of Raman Spectroscopy, 2020
Journal of Biophotonics, 2019
We demonstrate an accurate quantitative characterization of absolute two- and three-photon absorp... more We demonstrate an accurate quantitative characterization of absolute two- and three-photon absorption (2PA and 3PA) action cross sections of a genetically encodable fluorescent marker Sypher3s. Both 2PA and 3PA action cross sections of this marker are found to be remarkably high, enabling high-brightness, cell-specific two- and three-photon fluorescence brain imaging. Brain imaging experiments on sliced samples of rat's cortical areas are presented to demonstrate these imaging modalities. The 2PA action cross section of Sypher3s is shown to be highly sensitive to the level of pH, enabling pH measurements via a ratiometric readout of the two-photon fluorescence with two laser excitation wavelengths, thus paving the way toward fast optical pH sensing in deep-tissue experiments. This article is protected by copyright. All rights reserved.
Journal of Biophotonics, 2019
Methods of nonlinear optics provide a vast arsenal of tools for label-free brain imaging, offerin... more Methods of nonlinear optics provide a vast arsenal of tools for label-free brain imaging, offering a unique combination of chemical specificity, the ability to detect fine morphological features, and an unprecedentedly high, subdiffraction spatial resolution. While these techniques provide a rapidly growing platform for the microscopy of neurons and fine intraneural structures, optical imaging of astroglia still largely relies on filament-protein-antibody staining, subject to limitations and difficulties especially severe in live-brain studies. Once viewed as an ancillary, inert brain scaffold, astroglia are being promoted, as a part of an ongoing paradigm shift in neurosciences, into the role of a key active agent of intercellular communication and information processing, playing a significant role in brain functioning under normal and pathological conditions. Here, we show that methods of nonlinear optics provide a unique resource to address long-standing challenges in label-free astroglia imaging. We demonstrate that, with a suitable beam-focusing geometry and careful driver-pulse compression, microscopy of second-harmonic generation (SHG) can enable a high-resolution label-free imaging of fibrillar structures of astrocytes, most notably astrocyte processes and their endfeet. SHG microscopy of astrocytes is integrated in our approach with nonlinear-optical imaging of red blood cells based on third-harmonic generation (THG) enhanced by a three-photon resonance with the Soret band of hemoglobin. With astroglia and red blood cells providing two physically distinct imaging contrasts in SHG and THG channels, a parallel detection of the second and third harmonics enables a high-contrast, high-resolution, stain-free stereoimaging of gliovascular interfaces in the central nervous system. Transverse scans of the second and third harmonics are shown to resolve an ultrafine texture of blood-vessel walls and astrocyte-process endfeet on gliovascular interfaces with a spatial resolution within 1 μm at focusing depths up to 20 μm inside a brain. This article is protected by copyright. All rights reserved.
Journal of Raman Spectroscopy, 2019
Therapeutic Delivery, 2017
Most diseases and disorders of the brain require long-term therapy and a constant supply of drugs... more Most diseases and disorders of the brain require long-term therapy and a constant supply of drugs. Implantable drug-delivery systems provide long-term, sustained drug delivery in the brain. The present review discusses different type of implantable systems such as solid implants, in situ forming implants, in situ forming microparticles, depot formulations, polymeric-lipid implants, sucrose acetate isobutyrate and N-stearoyl L-alanine methyl ester systems for continuous drug delivery into brain for various brain diseases including glioblastomas, medulloblastoma, epilepsy, stroke, schizophrenia and Alzheimer's diseases. Implantable neural probes and microelectrode array systems for brain are also discussed in brief.
Neuroscience Letters, 2018
Chemistry of Materials, 2017
Journal of Raman Spectroscopy, 2016
Nature communications, Jan 22, 2017
Thermogenetics is a promising innovative neurostimulation technique, which enables robust activat... more Thermogenetics is a promising innovative neurostimulation technique, which enables robust activation of neurons using thermosensitive transient receptor potential (TRP) cation channels. Broader application of this approach in neuroscience is, however, hindered by a limited variety of suitable ion channels, and by low spatial and temporal resolution of neuronal activation when TRP channels are activated by ambient temperature variations or chemical agonists. Here, we demonstrate rapid, robust and reproducible repeated activation of snake TRPA1 channels heterologously expressed in non-neuronal cells, mouse neurons and zebrafish neurons in vivo by infrared (IR) laser radiation. A fibre-optic probe that integrates a nitrogen-vacancy (NV) diamond quantum sensor with optical and microwave waveguide delivery enables thermometry with single-cell resolution, allowing neurons to be activated by exceptionally mild heating, thus preventing the damaging effects of excessive heat. The neuronal re...
Laser Physics Letters, 2015
Optics and Spectroscopy, 2015
Optical physics and laser technologies are rapidly moving in the direction of exploring the midin... more Optical physics and laser technologies are rapidly moving in the direction of exploring the midinfrared spectral range. New methods of mid-IR ultrashort pulse generation allow forming very short flashes of electromagnetic radiation with record high peak power for this range. The first experiments conducted with such systems make possible implementing new regimes of laser–matter interaction and shed light on unusual properties of the nonlinear-optical response of materials in the mid-IR spectral range.
Optics letters, Jan 15, 2015
Strongly coupled nonlinear spatiotemporal dynamics of ultrashort mid-infrared pulses undergoing s... more Strongly coupled nonlinear spatiotemporal dynamics of ultrashort mid-infrared pulses undergoing self-focusing simultaneously with soliton self-compression in an anomalously dispersive, highly nonlinear solid semiconductor is shown to enable the generation of multioctave supercontinua with spectra spanning the entire mid-infrared range and compressible to subcycle pulse widths. With 7.9 μm, 150 fs, 2 μJ, 1 kHz pulses used as a driver, 1.2 cycle pulses of mid-infrared supercontinuum radiation with a spectrum spanning the range of wavelengths from 3 to 18 μm were generated in a 5 mm GaAs plate. Further compression of these pulses to subcycle pulse widths is possible through compensation of the residual phase shift.
AIP Conference Proceedings, 2010
In the early days of CARS, stimulated Raman scattering (SRS) has been successfully used to genera... more In the early days of CARS, stimulated Raman scattering (SRS) has been successfully used to generate the Stokes field for time-resolved measurements [1] of vibrational lifetimes of molecules in liquids and phonons in solids. Dye lasers and optical parametric sources ...
Journal of Modern Optics, 2010
ABSTRACT
Conference on Lasers and Electro-Optics, 2016
Photonics, 2021
We demonstrate an adaptive wave-front shaping of optical beams transmitted through fiber bundles ... more We demonstrate an adaptive wave-front shaping of optical beams transmitted through fiber bundles as a powerful resource for multisite, high-resolution bioimaging. With the phases of all the beamlets delivered through up to 6000 different fibers within the fiber bundle controlled individually, by means of a high-definition spatial light modulator, the overall beam transmitted through the fiber bundle can be focused into a beam waist with a diameter less than 1 μm within a targeted area in a biotissue, providing a diffraction-limited spatial resolution adequate for single-cell or even subcellular bioimaging. The field intensity in the adaptively-focused continuous-wave laser beam in our fiber-bundle-imaging setting is more than two orders of magnitude higher than the intensity of the speckle background. Once robust beam focusing was achieved with a suitable phase profile across the input face of the fiber bundle, the beam focus can be scanned over a targeted area with no need for a fu...
Nonlinear microscopy techniques are widely used in the field of biophotonics thanks to their abil... more Nonlinear microscopy techniques are widely used in the field of biophotonics thanks to their ability to image in highly scattering tissues such as brain [1]. Techniques that use intrinsic sources of contrast rather than exogenous labels are of great interest, because they are suitable not only for fundamental biological research but also for clinical applications [2]. Neurons are the most studied cells in the central nervous system of mammals. However, in certain parts of brain glial cells called astrocytes outnumber neurons. Historically, astrocytes considered to be simple support cells that structure the brain and control blood brain barrier, but recently were discovered to have great functional diversity and play many roles in healthy tissues as well as in CNS disorders [3].
Optics Letters, 2019
Polarization maps of high-order harmonics are shown to enable a full vectorial characterization o... more Polarization maps of high-order harmonics are shown to enable a full vectorial characterization of petahertz electron currents generated in a crystalline solid by an ultrashort laser driver. As a powerful resource of this methodology, analysis of energy-momentum dispersion landscapes, defined by the electron band structure, can help identify, as our analysis shows, special directions within the Brillouin zone that can provide a preferable basis for polarization-sensitive high-harmonic mapping of anisotropic petahertz photocurrents in solids.
Journal of Raman Spectroscopy, 2020
Journal of Biophotonics, 2019
We demonstrate an accurate quantitative characterization of absolute two- and three-photon absorp... more We demonstrate an accurate quantitative characterization of absolute two- and three-photon absorption (2PA and 3PA) action cross sections of a genetically encodable fluorescent marker Sypher3s. Both 2PA and 3PA action cross sections of this marker are found to be remarkably high, enabling high-brightness, cell-specific two- and three-photon fluorescence brain imaging. Brain imaging experiments on sliced samples of rat's cortical areas are presented to demonstrate these imaging modalities. The 2PA action cross section of Sypher3s is shown to be highly sensitive to the level of pH, enabling pH measurements via a ratiometric readout of the two-photon fluorescence with two laser excitation wavelengths, thus paving the way toward fast optical pH sensing in deep-tissue experiments. This article is protected by copyright. All rights reserved.
Journal of Biophotonics, 2019
Methods of nonlinear optics provide a vast arsenal of tools for label-free brain imaging, offerin... more Methods of nonlinear optics provide a vast arsenal of tools for label-free brain imaging, offering a unique combination of chemical specificity, the ability to detect fine morphological features, and an unprecedentedly high, subdiffraction spatial resolution. While these techniques provide a rapidly growing platform for the microscopy of neurons and fine intraneural structures, optical imaging of astroglia still largely relies on filament-protein-antibody staining, subject to limitations and difficulties especially severe in live-brain studies. Once viewed as an ancillary, inert brain scaffold, astroglia are being promoted, as a part of an ongoing paradigm shift in neurosciences, into the role of a key active agent of intercellular communication and information processing, playing a significant role in brain functioning under normal and pathological conditions. Here, we show that methods of nonlinear optics provide a unique resource to address long-standing challenges in label-free astroglia imaging. We demonstrate that, with a suitable beam-focusing geometry and careful driver-pulse compression, microscopy of second-harmonic generation (SHG) can enable a high-resolution label-free imaging of fibrillar structures of astrocytes, most notably astrocyte processes and their endfeet. SHG microscopy of astrocytes is integrated in our approach with nonlinear-optical imaging of red blood cells based on third-harmonic generation (THG) enhanced by a three-photon resonance with the Soret band of hemoglobin. With astroglia and red blood cells providing two physically distinct imaging contrasts in SHG and THG channels, a parallel detection of the second and third harmonics enables a high-contrast, high-resolution, stain-free stereoimaging of gliovascular interfaces in the central nervous system. Transverse scans of the second and third harmonics are shown to resolve an ultrafine texture of blood-vessel walls and astrocyte-process endfeet on gliovascular interfaces with a spatial resolution within 1 μm at focusing depths up to 20 μm inside a brain. This article is protected by copyright. All rights reserved.
Journal of Raman Spectroscopy, 2019
Therapeutic Delivery, 2017
Most diseases and disorders of the brain require long-term therapy and a constant supply of drugs... more Most diseases and disorders of the brain require long-term therapy and a constant supply of drugs. Implantable drug-delivery systems provide long-term, sustained drug delivery in the brain. The present review discusses different type of implantable systems such as solid implants, in situ forming implants, in situ forming microparticles, depot formulations, polymeric-lipid implants, sucrose acetate isobutyrate and N-stearoyl L-alanine methyl ester systems for continuous drug delivery into brain for various brain diseases including glioblastomas, medulloblastoma, epilepsy, stroke, schizophrenia and Alzheimer's diseases. Implantable neural probes and microelectrode array systems for brain are also discussed in brief.
Neuroscience Letters, 2018
Chemistry of Materials, 2017
Journal of Raman Spectroscopy, 2016
Nature communications, Jan 22, 2017
Thermogenetics is a promising innovative neurostimulation technique, which enables robust activat... more Thermogenetics is a promising innovative neurostimulation technique, which enables robust activation of neurons using thermosensitive transient receptor potential (TRP) cation channels. Broader application of this approach in neuroscience is, however, hindered by a limited variety of suitable ion channels, and by low spatial and temporal resolution of neuronal activation when TRP channels are activated by ambient temperature variations or chemical agonists. Here, we demonstrate rapid, robust and reproducible repeated activation of snake TRPA1 channels heterologously expressed in non-neuronal cells, mouse neurons and zebrafish neurons in vivo by infrared (IR) laser radiation. A fibre-optic probe that integrates a nitrogen-vacancy (NV) diamond quantum sensor with optical and microwave waveguide delivery enables thermometry with single-cell resolution, allowing neurons to be activated by exceptionally mild heating, thus preventing the damaging effects of excessive heat. The neuronal re...
Laser Physics Letters, 2015
Optics and Spectroscopy, 2015
Optical physics and laser technologies are rapidly moving in the direction of exploring the midin... more Optical physics and laser technologies are rapidly moving in the direction of exploring the midinfrared spectral range. New methods of mid-IR ultrashort pulse generation allow forming very short flashes of electromagnetic radiation with record high peak power for this range. The first experiments conducted with such systems make possible implementing new regimes of laser–matter interaction and shed light on unusual properties of the nonlinear-optical response of materials in the mid-IR spectral range.
Optics letters, Jan 15, 2015
Strongly coupled nonlinear spatiotemporal dynamics of ultrashort mid-infrared pulses undergoing s... more Strongly coupled nonlinear spatiotemporal dynamics of ultrashort mid-infrared pulses undergoing self-focusing simultaneously with soliton self-compression in an anomalously dispersive, highly nonlinear solid semiconductor is shown to enable the generation of multioctave supercontinua with spectra spanning the entire mid-infrared range and compressible to subcycle pulse widths. With 7.9 μm, 150 fs, 2 μJ, 1 kHz pulses used as a driver, 1.2 cycle pulses of mid-infrared supercontinuum radiation with a spectrum spanning the range of wavelengths from 3 to 18 μm were generated in a 5 mm GaAs plate. Further compression of these pulses to subcycle pulse widths is possible through compensation of the residual phase shift.
AIP Conference Proceedings, 2010
In the early days of CARS, stimulated Raman scattering (SRS) has been successfully used to genera... more In the early days of CARS, stimulated Raman scattering (SRS) has been successfully used to generate the Stokes field for time-resolved measurements [1] of vibrational lifetimes of molecules in liquids and phonons in solids. Dye lasers and optical parametric sources ...
Journal of Modern Optics, 2010
ABSTRACT
Conference on Lasers and Electro-Optics, 2016