Related Experiment Video
Updated: May 20, 2026

Ex Vivo Imaging of Cell-specific Calcium Signaling at the Tripartite Synapse of the Mouse Diaphragm
Published on: October 4, 2018
Integrated and compact fiber-coupled single-photon system based on nitrogen-vacancy centers and gradient-index lenses
Tim Schröder1, Philip Engel, Eberhard Schmidt
1Institute of Physics, Nano-Optics, Humboldt-Universität zu Berlin, 12489 Berlin, Germany. tim.schroeder@physik.hu‑berlin.de
Abstract:
A fiber-coupled single-photon system is presented. Gradient-index lenses are utilized for single-photon collection and fiber coupling of a nitrogen-vacancy defect center in a nanodiamond. Integrated filter technology separates excitation and laser light. Therefore, the system is ultracompact with 120 mm(3) in dimension as no bulky free beam optics are used. The commercial availability of all components and their simple assembly allows the implementation of a low-cost single-photon system, possibly approaching single-photon count rates of 500 kcts/s.
Related Concept Videos
Fluorescence and Phosphorescence: Instrumentation
Insensitive Nuclei Enhanced by Polarization Transfer (INEPT)
Confocal Fluorescence Microscopy
Phase Contrast and Differential Interference Contrast Microscopy
In-phase-contrast microscopes, interference between light directly passing through a cell and light refracted by cellular components is used to create high-contrast, high-resolution images without staining. It is the oldest and simplest type of microscope that creates an image by altering the wavelengths of light rays passing through the specimen. Altered wavelength paths are created using an annular stop in the condenser. The annular stop produces a hollow cone of...
Total Internal Reflection Fluorescence Microscopy
