In biology and biotechnology, photonics is used in many different ways.

  • Confocal laser scanning microscopy and computed microscopy have enabled 3D imaging of biological substances. The use of multi-photons imaging has opened interesting new possibilities, e.g. imaging inside living cells or fluorescence microscopy with resolutions well below the diffraction limit.
  • An optical fibre end-shaped into a cone and metallized on the side can be used to collect light in regions as small as a few tens of nanometres (near-field microscopy).
  • Fluorescent molecules or quantum dots replace radioactive tags rendering measurements much more practical and much safer.
  • Focused lasers can trap cells and other small objects (optical tweezers) and manipulate them at will.
  • Flow cytometry which is using lasers to excite fluorescence of cells in a liquid or gas flow can be used e.g. to realise a cell sorting. Lasers are essential to DNA sequencing and optics is being employed in a number of other biotechnology applications