A laser is an optical instrument that emits through an optical amplification process, based on the controlled discharge of electromagnetic radiation. It generates a very narrow and dense light beam. The term LASER is the short form for “Light Amplification by Stimulated Emission of Radiation”. It is an uncommon source of light that is very distinct from a flashlight or a light bulb. Light moves in the form of waves. The distance between consecutive peaks of a wave is known as the wavelength. Red light has a longer wavelength than blue light. In the case of a lightbulb, it emits light that has many wavelengths. Human eyes perceive this wavelengths’ mixture as white light. A laser is different from most conventional light devices. It only emits a narrow light beam in which all the light have identical wavelengths. The light waves of a laser move jointly with their peaks, all aligned up or in phase. Due to this, lasers have narrow light beams and are bright. This also enables it to be focused on a tiny point. Laser light rays always stay focused and do not scatter out extensively. They can also travel enormous distances and concentrate a huge amount of energy on a very small area.
A laser is a piece of equipment that emits light through a method of optical amplification formulated on the stimulated emanation of electromagnetic radiation. In 1917, Albert Einstein formulated the theoretical groundwork for the laser. It was based on Planck’s law of radiation, and conceptually built on probability coefficients for assimilation, impulsive emission, and stimulated emission of radiation. In the year 1928, Rudolf W. Ladenburg validated the existence of stimulated emission phenomena and negative absorption. Valentin A. Fabrikant predicted that stimulated emission could be used to amplify short waves in 1939. The first laser was constructed by Theodore H. Maiman (1960). It was developed based on the works of Arthur Leonard Schawlow and Charles Hard Townes.
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Lasers have many applications. They are used in barcode scanners, laser printers, DNA sequencing instruments, optical disk drives, optic fibre, laser surgery, skin treatments, semiconducting chip manufacturing, military devices for setting targets, measuring speed and range, etc. Apart from medical applications, lasers are also used in precision tools for cutting and moulding purposes (they can easily cut hard substances like metals and diamonds). Semiconductor lasers are also used instead of light-emitting diodes (LEDs) to activate fluorescence as a source of white light. This allows for a much smaller emitting region due to the much larger laser’s radiance, and eliminates the droop experienced by LEDs. Lasers are also used in apparatus called spectrometers. Such devices help scientists to understand what different materials are made of. In the case of planetary studies, lasers are used in tools that map the surfaces of moons, planets, and asteroids. Scientists have calculated the distance between the Earth and the moon using lasers. By calculating the amount of time required for a laser ray to travel to the moon and back, astronomers can accurately predict the exact distance between the Earth and the moon.
Important Laser Question with Answers
1) What is a laser?
A laser is an optical instrument that emits through an optical amplification process, based on the controlled discharge of electromagnetic radiation. It generates a very narrow and dense light beam. The term LASER is the short form for “Light Amplification by Stimulated Emission of Radiation”.
2) What are the unique characteristics of a laser?
A laser is an uncommon source of light that is very distinct from a flashlight or a light bulb. Light moves in the form of waves. The distance between consecutive peaks of a wave is known as the wavelength. Red light has a longer wavelength than blue light. In the case of a lightbulb, it emits light that has many wavelengths. Human eyes perceive this wavelengths’ mixture as white light. A laser is different from most conventional light devices. It only emits a narrow light beam in which all the light have identical wavelengths. The light waves of a laser move jointly with their peaks, all aligned up or in phase. Due to this, lasers have narrow light beams and are bright. This also enables it to be focused on a tiny point. Laser light rays always stay focused and do not scatter out extensively. They can also travel enormous distances and concentrate a huge amount of energy on a very small area.
3) How was the laser developed?
A laser is a piece of equipment that emits light through a method of optical amplification formulated on the stimulated emanation of electromagnetic radiation. In 1917, Albert Einstein formulated the theoretical groundwork for the laser. It was based on Planck’s law of radiation and conceptually built on probability coefficients for assimilation, impulsive emission, and stimulated emission of radiation. In the year 1928, Rudolf W. Ladenburg validated the existence of stimulated emission phenomena and negative absorption. Valentin A. Fabrikant predicted that stimulated emission could be used to amplify short waves in 1939. The first laser was constructed by Theodore H. Maiman (1960). It was developed based on the works of Arthur Leonard Schawlow and Charles Hard Townes.
4) What are the main uses of lasers?
They are used in barcode scanners, laser printers, DNA sequencing instruments, optical disk drives, optic fibre, laser surgery, skin treatments, semiconductor chip manufacturing, military devices for setting targets, measuring speed and range, etc. Apart from medical applications, lasers are also used in precision tools for cutting and moulding purposes (they can easily cut hard substances like metals and diamonds). Semiconductors lasers are also used instead of light-emitting diodes (LEDs) to activate fluorescence as a source of white light. This allows for a much smaller emitting region due to the much larger laser’s radiance and eliminates the droop experienced by LEDs. Lasers are also used in apparatus called spectrometers. Such devices help scientists to understand what different materials are made of. In the case of planetary studies, lasers are used in tools that map the surfaces of moons, planets, and asteroids. Scientists have calculated the distance between the Earth and the moon using lasers. By calculating the amount of time required for a laser ray to travel to the moon and back, astronomers can accurately predict the exact distance between the Earth and the moon.
5) Why are lasers hazardous?
Laser light is emitted in a compressed beam that does not expand in volume at a distance from the laser. This implies that the same extent of hazard can exist both close and far from the laser. The human eye can focus a laser ray on a very tiny, intense region on its retina, which can cause a severe burn or blind spot.
6) What are some of the main types of lasers?
The main types of lasers are Fiber Lasers, Semiconductor Lasers, Gas Lasers, Liquid Lasers, and Solid-State Lasers.
7) Lasers are characterized based on their _____ in a vacuum.
Answer: Wavelength
Explanation: Lasers are characterized based on their wavelength in a vacuum.
8) What is the difference between lasers and masers?
All stimulated light-emitting devices that operate at frequencies larger than microwaves are known as lasers. On the other hand, all devices that operate at microwave or lesser radio frequencies are known as masers.
9) What is the full form of maser?
The full form of maser is microwave amplification by stimulated emission of radiation.
10) What is the full form of laser?
The full form of laser is light amplification by stimulated emission of radiation.
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Practice Questions
1) What is the contribution of Albert Einstein in the field of lasers?
2) What is a maser?
3) Who invented the earliest prototype of lasers?
4) Scanners use _______ to read information.
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