The advancement of technology posits great help to the human race. And one of the breakthroughs of technology that is widely used today is a laser or light amplification by stimulated emission of radiation.
These high powered lasers have such mechanism of emitting electromagnetic radiation, typically light or visible light, via the process of stimulated emission. Through manipulation of lenses, the emitted light of high powered lasers is a spatial-coherent and narrow low-divergence beam.
Furthermore, coherent light refers to a light source where light of in-step waves of identical frequency and phase is produce and the high powered lasers’ beam of coherent light differentiates it from light sources that emit incoherent light beams, of random phase varying with time and position.
Generally, laser light is a narrow-wavelength electromagnetic spectrum monochromatic light; however, there are types of lasers where broad spectrum of light is emitted, or different wavelengths of light are simultaneously produced.
There are different types of laser technology, ranging form low to high power classes. High powered laser belongs to class IV (cw: 500 mW, pulsed: 10 J/cm2 or the diffuse reflection limit).
They are considered as hazardous to view under any condition (directly or diffusely scattered), and are a potential fire hazard and a skin hazard. Significant controls are required of Class IV high powered lasers facilities.
So how do a high powered lasers work? A laser consists of a gain medium inside a highly reflective optical cavity, as well as a means to supply energy to the gain medium.
The gain medium refers to a material where properties include allowing amplification of light through stimulated emission. In its simplest form, a cavity consists of two mirrors arranged such that light bounces back and forth, each time passing through the gain medium.
Typically, one of the two mirrors, the output coupler, is partially transparent. The output laser beam is then emitted through this mirror.
Since lasers are thought of as emitting light with a narrow wavelength spectrum (“monochromatic” light) typically, they are considered useful in many ways in various fields.
Though this might not be true to all types of lasers, however, there are some lasers that are cable to emit light with a broad spectrum – while others emit light at multiple distinct wavelengths simultaneously.
It is though that the coherence of typical laser emission is distinctive. Though there is a variation with time as well as position, most other light sources emit incoherent light.
How useful are these lasers really? History reveals that the first working laser was demonstrated by Theodore Maiman at Hughes Research Laboratories on May 16, 1960 and since then, lasers have become a multi-billion dollar industry covering various fields and working on with other different technologies.
We know as of today that one of the largest single applications of lasers is in optical storage devices such as compact disc and DVD players where a semiconductor laser less than a millimeter wide scans the surface of the disc.
On the other hand, the fiber-optic communication is the second largest. It can be noted that some other common applications of lasers widely used today are bar code readers, laser printers, and laser pointers among others.
Moreover, many manufacturing firms utilize lasers for cutting, bending, and welding metal and other materials, as well as for marking or producing visible patterns such as letters by changing the properties of a material or by inscribing its surface.
In the field of science, lasers are also proven very useful. In fact, lasers are used in laser spectroscopy, which typically takes advantage of the laser’s well-defined wavelength or the possibility of generating very short pulses of light. In military, lasers are used for range-finding, target designation and illumination.
Further, lasers are becoming useful in various weaponry. Lastly, some areas of medicine that have relied on laser technology are surgery, diagnostics, and therapeutic applications.