Application of laser
Laser is an intense, monochromatic, concentrated and coherent beam of light. It can be focused to a very small area. And hence the laser generates very high intensity in the area of focus. Because of this feature of characteristics, laser find widespread application. In the field of industry, medicine, communication, Defence, astronomy, chemistry, scientific research, environmental science, holographic, thermal nuclear fusion reaction etc.
Industrial Application of laser
A laser beam has the ability to concentrate large power on a small area. This property of laser is used in a number of industrial application like welding, cutting, making holes etc. These are the following application of laser use in industries.
In welding, a very high temperature is needed to melt and then join material. In the process of welding, material is added to join two components. For welding, laser beams must have high power rather than high peak power. Carbon dioxide laser and neodymium – YAG laser are most commonly used in welding. However, laser power should not be high to evaporate the material.
Lasers are used in the manufacturing of aircraft and automobiles. Laser welding is easily formed between two dissimilar metals. Hence, a Thermocouple can be easily welded to a substrate without damaging and neighbouring material.
Laser welding is also used effectively in electronics and microelectronics. Where precise welding of very thin wire and two thin film is required. Since laser welding is done in a very small interval of time. Therefore welding with laser is performed in a region in the neighborhood of the heat sensitive area without damaging or affecting the element.
For example, welding of part of a transistor is performed by a laser. Welding of components of inaccessible regions like inside a glass envelope can be done using lasers. The main advantage of laser welding over the gas or arc welding is that the purity of material welded is not altered or affected in case of laser welding.
The removal of a part of material along the cut from a substance is known as the cutting process. To cut metal or nonmetal like stainless steel, Titanium, ceramics,glass, plastic, wood, paper etc.
The repetition frequency of the pulse of a laser and the motion of the laser across the substance or material is adjusted in such a way that a series of overlapping holes are produced. Carbon dioxide laser is commonly used in the cutting process due to its output power.
The efficiency of laser cutting can be increased by making use of a gas Jet coaxial with the laser.
In cutting hard material like stainless steel, carbon steel, Titanium etc. A highly reactive gas like oxygen is used along with a laser beam. When a laser beam heats the material, it interacts with oxygen and get burnt.The Oxygen gas that also helps in expelling the molten material.
In cutting less hard material like good, plastic, paper etc. Inert gases like nitrogen and organ are used along with laser beams. This technique of cutting is very efficient for material absorbing most radiation of laser wavelength. The gas that you used helps in expelling the molten material.
Laser cutting is used in the aircraft and automobile industries, diamond industry and in the textile industry for cutting clothes.
Laser beam is used most effectively and efficiently to drill hole of very small diameter through the hardest material. Pulsed lasers can be burned through a 1 mm steel plate making a hole of diameter about 0.2 mm. Laser beams cut holes in diamond, one of the hardest materials.
Since laser beam can be focused on a very small area. Therefore, laser beam is used in micro machining. For example, one can write even on a human hair using a laser beam. The laser technique is used in crushing rocks and hands making tunnels in hard rock areas. Laser drilling is a very fast process and it has the advantage of precise location of the hole.
We can find the trajectory of any moving object like satellite, aircraft, rocket etc. And also we can find the daily position of Heavenly objects like the Moon, planet or any artificial satellite. The principle of laser tracking is the same as used in the Microwave radar system. In this method we measure the time taken to travel to and fro for a laser pulse sent by the observer to be reflected by the object and received back by the observer.
Application of Laser in medicine
Laser in eye surgery
Lasers have brought revolution in the field of medicine especially in eye surgery. The large scale use of lasers in eye surgery is due to the fact that the outer transparent region of the eye (i.e. cornea, iris, aqueous humor and lens). Allow light at suitable wavelength to pass through for subsequent absorption by the tissues at the back of the eye.
Laser beam is used in treating the detached retina. In this case, a laser beam (or laser pulse) is focused precisely at the desired spot on the retina where it produces a tiny spot weld ( typical diameter of the spot is about 50 micro meter).
Lasers are also used for vision correction. LASIK ( Laser In-Sites Keratomileusis ) surgery is used to treat vision correction ( i.e. focussing defects) of the eye. In this technique, cornea of the eye is crafted to adjust its curvature. So that the proper focussing of light by the eye lens takes place on the retina.
It is also used in curing cataract and glaucoma.
- Lasers are used in cutting and sealing the small blood vessel in brain operation.
- The lasers are used in skin cancer treatment.
- Lasers are used for treating burn wounds.
- The Lasers are used in the treatment of Pulmonary tuberculosis.
- Lasers are used to destroy tumors.
- Laser induced fluorescence (LIF) from human tissues is used for early detection of cancer due to easy accessibility of the organ.
Laser which are used in medicine are
- CO2 laser
- Diode laser
- Dye laser
- Excimer laser
- Fibre laser
- Gas laser
- Free electron laser
- Semiconductor laser