Laser Technology
A REPORT ON LASER
1
Techno India College of Technology
Megacity,Rajarhat Kolkata 700156
A Report on
LASER TECHNOLOGY
By
ZAKIR UDDIN AHMAD
Student B.Tech 3rd year Applied Electronics and Instrumentation Engineering
2012
2
Abstract
The word laser is an acronym that stands for "light amplification by stimulated emission of radiation." In a fairly unsophisticated sense, a laser is nothing more than a special flashlight. Energy goes in, usually in the form of electricity, and light comes out. But the light emitted from a laser differs from that from a flashlight, and the differences are worth discussing. You might think that the biggest difference is that lasers are more powerful than flashlights, but this conception is more often wrong than right. True, some lasers are enormously powerful, but many are much weaker than even the smallest flashlight. So power alone is not a distinguishing characteristic of laser light. But for now it 's enough to say that there are three differences between light from a laser and light from a flashlight. First, the laserbeam is much narrower than a flashlight beam. Second, the white light of a flashlight beam contains many different colors of light, while the beam from a laser contains only one, pure color. Third, all the light waves in a laserbeam are aligned with each other, while the light waves from a flashlight are arranged randomly. The significance of this difference will become apparent as you read about the nature of light. Lasers come in all sizes—from tiny diode lasers small enough to fit in the eye of a needle to huge military and research lasers that fill a three-story building.And different lasers can produce many different colors of light. The "light" produced by carbon dioxide lasers and neodymium lasers cannot be seen by the human eye because it is in the infrared portion of the spectrum. Interestingly, few of these lasers produce even as much power as an ordinary 100-W lightbulb. What 's more, lasers are not
1
Techno India College of Technology
Megacity,Rajarhat Kolkata 700156
A Report on
LASER TECHNOLOGY
By
ZAKIR UDDIN AHMAD
Student B.Tech 3rd year Applied Electronics and Instrumentation Engineering
2012
2
Abstract
The word laser is an acronym that stands for "light amplification by stimulated emission of radiation." In a fairly unsophisticated sense, a laser is nothing more than a special flashlight. Energy goes in, usually in the form of electricity, and light comes out. But the light emitted from a laser differs from that from a flashlight, and the differences are worth discussing. You might think that the biggest difference is that lasers are more powerful than flashlights, but this conception is more often wrong than right. True, some lasers are enormously powerful, but many are much weaker than even the smallest flashlight. So power alone is not a distinguishing characteristic of laser light. But for now it 's enough to say that there are three differences between light from a laser and light from a flashlight. First, the laserbeam is much narrower than a flashlight beam. Second, the white light of a flashlight beam contains many different colors of light, while the beam from a laser contains only one, pure color. Third, all the light waves in a laserbeam are aligned with each other, while the light waves from a flashlight are arranged randomly. The significance of this difference will become apparent as you read about the nature of light. Lasers come in all sizes—from tiny diode lasers small enough to fit in the eye of a needle to huge military and research lasers that fill a three-story building.And different lasers can produce many different colors of light. The "light" produced by carbon dioxide lasers and neodymium lasers cannot be seen by the human eye because it is in the infrared portion of the spectrum. Interestingly, few of these lasers produce even as much power as an ordinary 100-W lightbulb. What 's more, lasers are not
Bibliography: P. Zorabedian, Tunable external cavity semiconductor lasers, in Tunable Lasers Handbook, F. J. Duarte (Ed.) B. Docter, S. Beri, F. Karouta, M.K. Smit, “Semiconductor laser device,” International patent #PCT/NL/2008/000185, filed August 01, 2008 www.forumscollegelib.com 15