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Lasers for optical tweezing

Optical tweezers, also known as optical traps, were first introduced in 1986 and since then have been widely used in different applications, being particularly successful in the field of biological studies, where optical tweezers are used to study DNA sequences, interactions of proteins, etc.
Optical tweezers have been used in numerous studies which involve optical tweezers in order to trap single atoms, viruses, single-cell organisms, strands of DNA, bacteria, carbon nanostructures and many others. The manipulation and assembly of structures on a nanoscale are the most promising advances right now.
The main principle of optical tweezing lies in the fact that light carries momentum that is in proportion to its energy, and the direction of light is the same as the direction of propagation. After interacting with an object, light beam changes its momentum; same happens with an object after interaction with a beam of light – it undergoes a change of momentum by an equal amount. These interactions result in a reaction force, which acts on the object.
In most optical tweezer set ups, light is emitted by a laser beam which is focused on a particular spot. A trap, that is able to hold a small dielectric object, appears in the spot. The scattering force, that occurs when light hits the object and scatters by its surface, produces a momentum transfer that leads to the object being pushed to the beam of light. This method allows to trap an object in all dimensions.
It is critical that lasers used to create an optical trap are highly stable. Ytterbium lasers are often used in optical tweezer systems as they produce a stable and high-power laser beam which allows for interference-free optical trapping. Other properties of Yb lasers include:

  • a simple electronic level structure;
  • a small quantum defect, which provides an opportunity for high power efficiency;
  • Yb lasers have a capacity for wide wavelength tuning;
  • a low-noise beam that allows to create an optical trap in a precise spot.

All of these characteristics make Ytterbium lasers one of the most optimal options for light emitters in optical tweezer systems. These lasers have already been used in multiple studies that utilize optical trapping for capturing micron-sized particles and living cells, superior pointing stability being the main reason these lasers are chosen over other types.
Optromix provides Ytterbium lasers that can be used in optical tweezing with great efficiency. If you would like to purchase Ytterbium lasers, please contact us at or +1 617 558 98 58.