LASER stands for Light Amplification by Stimulated Emission of Radiation and MASER stands for Microwave Amplification by Stimulated Emission of Radiation. A LASER is a MASER that works with higher frequency photons in the ultraviolet or visible light spectrum.
Properties of Laser:
The important features possessed by laser beam are-
The laser beam is extremely monochromatic i.e., it consists of radiations of possessing the same wavelength and frequency.
Lasers emit radiation in a highly directional, collimated beam with a low angle of divergence.
One of the characteristics of stimulated emission is that the stimulated wave is in phase with the stimulating wave. It means that the spatial and temporal variation of the electric field of the two waves is the same. Thus for a perfect laser, the electric field varies with time in an identical fashion for every point on the beam cross-section.
The primary characteristic of laser radiation is that the lasers have a higher brightness than any other light source.
Applications of Laser:
Following are the applications of Laser-
It can be used in surgery, operation of human retina, treatment of cancer, localized treatment of skin growth and blemishes. The diseased tissues can be cut without bleeding and cuts can also be joined with the help of laser beams.
In Welding and Cutting:
The automobile industry makes extensive use of carbon dioxide lasers with powers up to several kilowatts for computer controlled welding on auto assembly lines.
Laser beams are used to transmit the signals from one place to another using glass fibers. Laser beams can carry thousand of signals at a time. Due to the narrow bandwidth, high intensity, and high frequency of laser beam, it is widely used in communication between the earth and the satellites.
In Laser Printers:
The laser printer has become the dominant mode of printing in offices. It employs a semiconductor laser and the xerography principle. The typical laser for this application is the aluminum-gallium-arsenide laser at 760nm wavelength.
A laser beam is projected in a particular direction without the loss in its energy. Because of this property, it can be used to measure the precise distance between two objects. For example- the exact distance between earth and moon has been calculated.
It can be used for drilling of diamonds, machining, welding, soldering, and forming of holes and slots in refractory materials, metals carbides, and tungsten as laser beam is very powerful.
These have been used in high-speed photography. For example- bullets travelling at very high speeds have been photographed.
Applications of Maser:
Crystals containing paramagnetic ions can be used as maser materials. For example- pink ruby, Ammonia gas. Masers are used in-