BE-OPTICAL

Wide-field multiphoton imaging through scattering media without correction

Courtesy of Adrià Escobet-Montalbán (ESR1 at University of St. Andrews, St. Andrews, UK). A TF beam propagates through a turbid medium with minimal distortion, retaining the integrity of illumination patterns in the sample plane. Emitted fluorescent photons scatter as they propagate back through the tissue. In contrast to standard TF microscopy, TRAFIX tolerates scrambling of back-propagating light since only an intensity measurement is performed. In a single-pixel measurement, the fluorescent target is sequentially illuminated with Hadamard patterns (ψn), and the total intensity detected is stored as a coefficient (ωn). Gray background in the second column denotes regions of zero intensity. By adding up the Hadamard patterns weighted by their respective coefficients, an image of the fluorescent sample is reconstructed. Find out more at A. Escobet-Montalbán, R. Spesyvtsev, M. Chen, W. Afshar Saber, M. Andrews, C. Simon Herrington, M. Mazilu and K. Dholakia, "Wide-field multiphoton imaging through scattering media without correction", Sci. Adv. 10(4) 2018

First fundus camera image acquired at 1050 nm. Preliminary results

Courtesy of Tommaso Alterini (ESR8 at Universitat Politècnica de Catalunya, Barcelona, Spain). (a) Hyperspectral imaging system for the dynamic recording of the ocular fundus. (b) Ocular fundus image acquired illuminating the retinal layer with LEDs which peak wavelength is 670 nm. (c) Ocular fundus image acquired illuminating the retinal layer with LEDs which peak wavelength is 1050 nm.

Fast visible and extended near-infrared multispectral fundus camera

Courtesy of Tommaso Alterini (ESR8 at Universitat Politècnica de Catalunya, Barcelona, Spain) (a) Internal view of the multispectral fundus camera. (b) Color (RGB) image acquired with a mydriatic retinal camera and spectral images taken with the multispectral fundus camera of an eye with drusen-induced RPE degeneration. While the degeneration is hardly visible in the color image, it can be clearly seen in some red and infrared images. Find out more at: T. Alterini, F. Díaz-Doutón; F. J. Burgos-Fernández, L. González, C. Mateo and M. Vilaseca, “Fast visible and extended near-infrared multispectral fundus camera,” J. Biomed. Opt. 24(9), 096007 (2019)

The SS-OCT prototype

Courtesy of Ana Rodríguez-Aramendía (ESR9 at Institut de Microcirurgia Ocular (IMO), Barcelona, Spain) (a) The SS-OCT prototype permits to change from an anterior segment imaging modality (red) to a retinal imaging modality (pink) by means of a fold mirror in the sample arm and adapting the length of the reference arm. (b) SS-OCT prototype installed in a clinical setting, where it is undergoing a clinical study. The system counts with a joystick-controlled chin rest and forehead rest for easy patient alignment. (c) Anterior segment (up) and retinal (down) OCT image of a healthy volunteer imaged with the developed SS-OCT instrument.

Multi-plane phase contrast 3D imaging system

Courtesy of Soheil Mojiri (ESR1 at Georg August University, Göttingen, Germany). Schematic of multi-plane phase contrast setup. a) Phase annulus conjugated with a phase objective provides phase contrast image. Focal planes and different optical paths are shown in eight different colors. Multi-channel beam splitter directs the phase contrast light emitting from eight distinct axially spaced planes inside the specimen onto four adjacent field of view on each of two cameras. An additional telescope comprising by L1 and L2 are used to project images on camera sensors. d, n, Ma and L1z denote respectively constant displacement path of prism, refractive index of prism, axial magnification and inter-plane distance. The adjustable field aperture determines the number of pixels in image window on camera and avoids overlapping between side by side images. b) Different frames of the multi-plane phase contrast image of Chlamydomonas falgella. Height of sample from surface is color coded.

Experimental characterization of the speckle pattern at the output of a multimode optical fiber

Speckle pattern recorded by Donatus Halpaap (ESR11 at Universitat Politecnica de Catalunya in Barcelona, Spain) using a diode laser and a multimode fiber. In imaging systems speckle often needs to be supressed because it degrades the image quality; however, in many applications, speckle is actually useful because it contains information about the light and the object that generates the speckle. By simultaneously varing the laser pump current and the camera exposure time, images with similar average intensity, but with very low or very high speckle contrast have been recorded. Find out more at: D. Halpaap, J. Tiana-Alsina, M. Vilaseca and C. Masoller, “Experimental characterization of the speckle pattern at the output of a multimode optical fiber”, Opt. Express 27, 27738 (2019)

Unsupervised feature extraction of anterior chamber OCT images for ordering and classification

Map of ocular images (anterior-chamber optical coherence tomography OCT images) revealing different degrees of angle-closure (a glaucoma diagnostic), which was obtained by using unsupervised machine learning algorithms based on nonlinear dimensionality reduction. Work done by Pablo Amil (ESR14 at Universitat Politecnica de Catalunya in Barcelona, Spain) with the collaboration of researchers at the Max Planck Institute for Dynamics and Self Organization (Gottingen, Germany) and ophthalmologists of the Institut de Microcirugia Ocular (Barcelona, Spain). Find out more at: P. Amil, L. Gonzalez, E. Arrondo, C. Salinas, J.L. Guell, C. Masoller, and U. Parlitz, “Unsupervised feature extraction of anterior chamber OCT images for ordering and classification”, Sci. Rep. 9, 1157 (2019)

TempoRAl Focusing microscopy with single-pIXel detection (TRAFIX) principle of operation

Courtesy of Adrià Escobet-Montalbán (ESR1 at University of St. Andrews, St. Andrews, UK). TRAFIX is a ground-breaking microscope capable of revealing ‘hidden’ processes responsible for diseases such as cancer. It obtains wide field-of-view images from inside scattering media like tissue without any prior knowledge of the target or the image, by using a combination of techniques including temporal focusing and single-pixel detection. Find out more at: A. Escobet-Montalbán, R. Spesyvtsev, M. Chen, W. Afshar Saber, M. Andrews, C. Simon Herrington, M. Mazilu and K. Dholakia, "Wide-field multiphoton imaging through scattering media without correction", Sci. Adv. 10(4) 2018

Three-photon light-sheet fluorescence microscopy

Courtesy of Adrià Escobet-Montalbán (ESR1 at University of St. Andrews, St. Andrews, UK). First demonstration of three-photon excitation light-sheet fluorescence microscopy. Find out more at
https://www.osapublishing.org/ol/abstract.cfm?uri=ol-43-21-5484

Imaging and Analysis Tools for Optogenetic Cardiac Electrophysiology

Courtesy of Vineesh Kappadan (ESR4 at Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany). Optogenetic arrhythmia termination of a murine heart using a 10 ms pulse.

Fluorescence imaging of contracting intact heart

Courtesy of Raúl Quiñonez Uribe (ESR5 at Max Planck Institute for Dynamics and Self-Organization, Göttingen, Germany). Multi Parametric Optical Mapping.

Oscillating Chlamydomonas flagella in 3D aquierd by the multi-plane phase contrast 3D imaging system

Courtesy of Soheil Mojiri (ESR1 at Georg August University, Göttingen, Germany). Oscillating Chlamydomonas flagella in 3D aquierd by the 3D imaging system (multi-plane phase contrast imaging)