The laser has contributed to humanity as a powerful scientific tool for expanding human knowledge and in its many applications that help people directly. It has been put to work in a vast range of applications and has assumed many forms.
In communications:
Engineers recognized the potential of the laser to replace electrical transmission over copper wires, but how to transmit the pulses presented enormous problems. In 1960, Some Scientists transmitted pulses of light a distance of 25 miles the laser produced an intense and extremely narrow beam of light that was more than a million times brighter than the sun.
In Search of a medium:
Unfortunately, Laser beam is easily affected by atmospheric conditions, such as rain, fog, low clouds, and objects in the air, like birds. Scientists suggested a number of novel schemes to protect the light from interference, including shielding it in metal tubes and using specially designed mirrors and thermal gas lenses to navigate around bends.
In Telecommunications:
Telecommunications relies today on photons, as tiny semiconductor lasers transmit light pulses carrying billions of bits of information per second over glass fibers. Wavelength division multiplexing technology uses various wavelengths, or colors, of light to transmit trillions of bits simultaneously over a single fiber.
In medicine:
Laser is used in the field of medicine after inventing the carbon dioxide laser, which soon permitted surgeons to perform highly intricate surgery using photons, rather than scalpels, to both operate on and cauterize wounds. Lasers today can be inserted inside the body, performing operations that a few years ago were almost impossible to perform.
Today, lasers are also used in a wide range of applications in medicine, manufacturing, the construction industry, surveying, consumer electronics, scientific instrumentation, and military systems. Literally billions of lasers are at work today. They range in size from tiny semiconductor devices no bigger than a grain of salt to high-power instruments as large as an average living room.