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Expanding applications of fiber laser technology
Laser systems become an integral part of human life; fiber laser technology continues to develop, leading to the appearance of new applications and expanding the old ones. For instance, a team of scientists from Japan has presented novel linear nanomotors that can be moved in controlled directions by applying a laser beam.
These fiber lasers used in nanomotors make it possible to develop new microfluidics and lab-on-a-chip systems with optically actuated pumps and valves or other devices based on fiber laser technology that can be previously challenging or even impossible to perform.
Challenges of nanoscale devices
Nanoscale devices greatly differ from the ones involving the contraptions that researchers have used to employed. For example, it is more challenging to produce and accurately control a nanomotor (the tiny motor that is smaller than a bacterium) based on the laser system than to drive a car.
Development of gold nanorod-based motors
The recent development of the Japanese team includes a fiber laser system used in linear motors made from gold nanorods that allow for moving in a controlled direction when subjected to a laser beam. The operating principle is similar to a sailboat that can be directed in any desired position.
Principles of nanomotor operation
Such nanomotors’ operation does not lead to following the direction of the laser beam. Their operation is based on the orientation, even when they are subjected to a laser beam emitting from another angle. Thus, the laser system moves due to the lateral optical force produced by the sideways scattering of the laser beam from the particles.
Advantages of the new fiber laser system
There is no need to direct or shape the laser beam with lenses, which was quite challenging previously. Compared to previous systems, the wavelength of light produced by the fiber laser does not influence or limit the size of new nanomotors.
Key role of plasmon resonance
The laser beam or the field gradient does not define the motion and does not restrain it; the direction is based on the orientation of the nanoparticles themselves. “The key to this fiber laser technology is the localized surface plasmon resonance – collective oscillations of free electrons – within periodic arrays of nanorods.” They emit a scattered laser beam in a particular direction.
Future applications of nanomotors
The team of scientists plans to apply this fiber laser system to develop a new platform for nano-sized devices with moving parts that follow predetermined paths while being directed by unfocused laser beams. Thus, they claim the cost and complexity of such systems can be significantly reduced while accuracy and robustness will increase.