From their inception as flash pump systems in the 1960s, lasers have evolved at a remarkable rate. Today laser markers are used around the world in communication, construction, manufacturing, medical and military industries.
With the variety of laser marking systems on the market today, choosing the right one for an application requires understanding their unique characteristics and capabilities. This mini-series will explain what lasers are, different laser types and what effect these differences have on marking and processing.
LASER stands for Light Amplification by Stimulated Emission of Radiation. Lasers are beams of artificial light that differ vastly from natural light in 4 critical areas, allowing them to be utilized in a variety of fields.
Natural light is comprised of wavelengths ranging from ultraviolet to infrared. By comparison, lasers beams have a single wavelength. This characteristic is called monochromaticity, and it allows greater flexibility in optical design.
Natural light passing through a lens expands depending on its wavelength. This is called chromatic aberration. Since a laser only has a single wavelength it is only refracted in one direction. This enables lens designs that transmit laser beams over great distances and concentrate the laser onto a small spot.
Directionality is the property of maintaining the direction of sound or light as it travels through space. A high directionality indicates that this direction is maintained to a high degree with small expansion.
Natural light is a collection of beams that propagate in every direction. To increase the directionality of natural light, complicated optical systems that eliminate all but the desired wavelength are necessary. Laser light has high directionality, making it easy to design optical systems that transmit the light over long distances without losing power.
Coherence describes the degree to which light interferes with itself. Considering light as a wave, greater uniformity results in higher coherence. This is similar to how waves colliding on the surface of water strengthen or negate each other. The more random a wave is, the weaker its degree of interference.
Because the phase, wavelength, and direction of laser light is the same, it is possible to maintain a strong wave and transmit laser beams over a long distance without suffering diffusion. This makes it possible to concentrate the light into a small spot with a lens.
Lasers have excellent monochromaticity, directionality, and coherence. They can be concentrated into an extremely small beam spot. These features make it possible to create light with a high energy density.
It is possible to concentrate laser light nearly to the diffraction limit, which is not possible with natural light. The diffraction limit exists because it is impossible to concentrate light smaller than its wavelength. By concentrating laser light into a small beam, it is possible to increase the intensity (power density) of the light to the point where fiber laser engraving machines can cut metal.
KEYENCE has been an innovative leader in the laser marking industry since the early 1990’s. Our high speed, precision processing capabilities have evolved to include the world's first 3-Axis lasers and unrivaled marking quality among UV, Fiber and CO2 systems. The newest laser markers from KEYENCE are built upon years of experience and hands-on application knowledge. KEYENCE is committed to introducing new cutting-edge products that go beyond the expectations of its customers.
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