Optical tweezing, also known as optical manipulation or optical trapping, is a technique that allows the capture and movement of small particles using highly focused laser light.
Lasers for optical tweezers
As laser light is focused onto a particle, it experiences a change of refractive index and slightly changes its direction of travel, moving along the gradient in electrical field strength. This exerts an opposite force on the particle and, if the particle is smaller than the light beam itself, causes it to be ‘trapped’ in the center of the beam waist, where the electric field strength is at a maximum.
This has proved to be a highly useful tool in many fields. Everything from individual atoms, custom micro-machines, and biological cells are being manipulated using this technique. Most biological samples are undamaged by NIR radiation, such as 1064 nm. As such, scientists can now easily isolate individual bacteria and viruses for study without mechanically interfering with them.
Key to this technique, to gain a ‘firm grip’ on the particles, is exceptional power and pointing stability, along with excellent beam circularity and low noise.
UniKLasers design and manufacture high power, single frequency laser sources with exceptional beam quality over a range of wavelengths within a small footprint. We currently offer single frequency lasers in the red area of the visible spectrum with our 640 Series Laser and with our ultraviolet 349 NX Laser to facilitate biological measurements over a range of applications.