Optical trapping, laser tweezers and Raman spectroscopy
10 Apr 2015



Microscopy and Tweezers


Aerosol caught in an opposing laser trap


Contact: Dr. Andy Ward

The capture of microscopic particles with laser light can be performed with single laser beams using high numerical aperture objectives (Laser Tweezers), or with lower numerical aperture optics where another force is present such as gravity, an interface or an opposing laser (Laser Trapping). We offer both trapping techniques and combine these with other imaging techniques to meet experimental requirements. Typical combinations are with Force measurement, Raman spectroscopy, Mie scattering spectroscopy, Confocal microscopy and Fluorescent Lifetime Imaging microscopy. For Raman spectroscopy we frequently, but not exclusively, use the trapping wavelength as the Raman probe.

Samples are typically polymer beads, emulsions, bacteria and cells dispersed in liquids. We can also offer airborne trapping of droplets and solids below 10 microns diameter and options for atomisation and nebulisation.

​Microscope Specification

Instrument Optical trapping and Raman spectroscopy
Laser wavelengths 488, 514.5, 532, 700-900, 1064 nm
Compatible objective lenses 100x oil immersion, 63x oil immersion, 63x water immersion. Long working distance 100x and 50x air.
Raman spectroscopy ranges 450 – 700 nm Acton spectrograph\PI Spec 10 detector
600 – 1000 nm Acton spectrograph\PI Spec 10 detector
900 – 1700 nm Isoplane spectrograph\PI NIRvana detector
Temperature control 5-90 °C



Colloid and interface science, medical research, atmospheric chemistry, aerosol science, material science, biological research, plant cell studies, catalysis.

Case Studies

Contact: Ward, Andy (STFC,RAL,CLF)