LASER Technology: Key Points & Top 25 MCQs for UPSC Exams
Have you ever wondered how a strong light beam, which can cut a substance, see inside the body, and transfer data, works? If you are interested in science, technology, or medicine, then it is very important for you to understand LASER Technology. This technology is a revolutionary discovery of the modern era, which is being used not only in industries but also in medicine, communication, defense, space, and entertainment. In this article, you will learn the principles, types, uses, advantages, challenges, and related online courses, books, and websites of lasers.
Laser Technology – Key Concepts and Applications
| Concept | Details |
|---|---|
| Laser Technology | A technique that amplifies light through stimulated emission of radiation for precise and powerful applications. |
| Laser Types | Includes gas lasers, solid-state lasers, fiber lasers, and semiconductor lasers used in different industries. |
| Laser Applications | Used in surgery, communication, industry, entertainment, defense, and scientific research. |
| Laser Cutting | Precision tool for cutting metals, plastics, and textiles with high speed and accuracy. |
| Laser Treatment | Widely used in dermatology, ophthalmology, and cancer therapy for non-invasive procedures. |
What is LASER technology?
Light Amplification by Stimulated Emission of Radiation is the complete abbreviation of the laser.
A laser is a peculiar kind of light beam that sends forth light at the same wavelength in a coherent way.
-
This beam is extremely intense, narrow, and focused, which can provide intense energy at a point.
-
Laser devices have an active medium (such as gas, solid matter, or crystal), which is activated by electrical or light energy.
-
Principles such as stimulated emission, population inversion, and optical resonators are used to generate laser beams.
-
This technology is opening new dimensions in areas such as processing, measurement, communication, medicine, and security.
What are the types of lasers?
Laser technology has different types of lasers, which are classified based on use, medium, and power.
-
Gas Laser – CO₂ laser technology is used in industrial cutting and surgery in the medical field.
-
Solid-State Lasers—These use ruby or Nd: YAG crystals (Yttrium Aluminum Garnet), effective in medicine and the military.
-
Diode Laser—These are used in small electronic devices, such as CD/DVD players, barcode scanners, and fiber optics.
-
Fiber Laser – These have excellent beam quality and are ideal for high-speed cutting.
-
Excimer Laser—This is an ultraviolet laser, which is used in LASIK surgery (Laser-Assisted In Situ Keratomileusis—reshaping the cornea) of the eyes.
.webp "Various applications of laser technology")
What are the applications of LASER?
Laser technology is being used in every major field today—its uses are very wide.
-
In medicine, lasers are used in surgery, skin treatment, vision correction (LASIK),, and cancer treatment.
-
In industries, lasers are widely used in metal cutting, welding, drilling, and 3D printing.
-
In the communication field, laser beams are used to transfer data through optical fibers.
-
It is extremely useful in military applications, such as missile detection, laser-guided weapons, and focusing on enemy positions.
-
In entertainment, it is used in laser light shows, laser projectors, and theme parks.
What are the advantages of Laser Technology?
Laser technology has made many tasks more precise, faster, and safer.
-
This technology can work with high accuracy even in zero contact, reducing the chances of harm.
-
In the medical field, surgery can be done without incision by laser, which leads to faster recovery of the patient.
-
In industry, it is used to increase the production rate and maintain better quality.
-
In optical communication, it makes data transfer more rapid and reliable.
-
It is an environmentally friendly technology, as it produces less waste and noise.
Applications of LASER in Various Fields
| Field | Application of LASER |
|---|---|
| Medicine | Used in eye surgeries, dermatology, dental procedures, and cancer treatments for precision and minimal invasiveness. |
| Industry | Employed in cutting, welding, engraving, and material processing with extreme accuracy and speed. |
| Defense | Used for target designation, range-finding, missile guidance, and developing directed energy weapons. |
| Communication | Fiber optic communication uses LASERs for high-speed data transmission over long distances with minimal loss. |
| Entertainment | LASER light shows, projection mapping, and special effects in concerts and events utilize laser beams for visual impact. |
| Scientific Research | Used in spectroscopy, holography, atomic trapping, and quantum computing experiments in physics and chemistry. |
What precautions to be taken against the dangers of laser technology?
While lasers are useful, they can also have dangerous consequences if precautions are not taken.
-
High-powered lasers can cause permanent damage to the skin or eyes; they should not be used without special equipment.
-
Laser radiation can damage biological tissue, which can lead to DNA damage.
Cyberattacks, data theft, and accidents can result from improper handling or inadequate system security.
-
High costs and the need for expertise have not made it accessible to every sector.
-
In some cases, the use of laser technology in weapons raises ethical questions.
What is the status of laser technology in India?
Laser technology is also developing rapidly in India, especially in defense, medicine, and industry.
-
Institutions like DRDO, ISRO, and BARC are working on laser technology in the defense and space sectors.
-
In the medical sector, their use in laser-based surgery and dental clinics has increased significantly.
-
Research and education on laser technology are being carried out in IITs, IISc, and national laboratories.
-
Indian startups are also working on laser cutting, metal fabrication, and 3D marking machines.
-
Research on laser-based weapons and surveillance systems is ongoing in the defense sector.
Top 25 MCQs on LASER Technology for UPSC Exams
Practice the Top 25 MCQs on LASER Technology to sharpen your understanding of core concepts, improve analytical accuracy, and boost confidence for UPSC prelims and other competitive examinations.
1. What does the acronym "LASER" stand for?
a) Light Amplification by Stimulated Emission of Radiation
b) Light Absorption by Stimulated Energy Release
c) Linear Amplification of System Energy Radiation
d) Light Alternation by Solar Energy Reflection
Expand Text
Answer: a) Light Amplification by Stimulated Emission of Radiation
The name describes the physical principle: "Stimulated Emission," where an incoming photon encourages an excited atom to release a second, identical photon.
2. Who theorized the concept of "Stimulated Emission," the core principle of lasers, in 1917?
a) Isaac Newton
b) Albert Einstein
c) Thomas Edison
d) Niels Bohr
Expand Text
Answer: b) Albert Einstein
Einstein proposed that an excited atom could return to a lower energy state by emitting a photon when struck by another photon of the same energy.
3. Which unique property of laser light means all the light waves are "in step" (peaks align with peaks)?
a) Monochromaticity
b) Coherence
c) Polarization
d) Diffraction
Expand Text
Answer: b) Coherence
Coherence means the light waves maintain a fixed phase relationship (spatial and temporal), allowing the beam to travel long distances without spreading.
4. What condition must be achieved for a laser to work, where more atoms are in an excited state than in the ground state?
a) Population Explosion
b) Population Inversion
c) Ground Saturation
d) Thermal Equilibrium
Expand Text
Answer: b) Population Inversion
Usually, atoms prefer the ground state. "Pumping" energy forces them into a higher state (inversion) so stimulated emission can dominate over absorption.
5. Who built the world's first working laser (the Ruby Laser) in 1960?
a) Theodore Maiman
b) Gordon Gould
c) C.V. Raman
d) Alexander Bell
Expand Text
Answer: a) Theodore Maiman
He used a synthetic ruby crystal pumped by a high-power flash lamp to produce red laser light at Hughes Research Laboratories.
6. "LIDAR" technology uses laser pulses to measure distances. What does LIDAR stand for?
a) Light Identification and Ranging
b) Light Detection and Ranging
c) Laser Infrared Detection and Reading
d) Long Intense Distance and Radar
Expand Text
Answer: b) Light Detection and Ranging
LIDAR is crucial for autonomous vehicles and topographic mapping. It calculates distance by measuring the time it takes for a laser pulse to return.
7. Which type of laser is most commonly used in LASIK eye surgery to reshape the cornea?
a) CO2 Laser
b) Excimer Laser
c) Ruby Laser
d) Semiconductor Laser
Expand Text
Answer: b) Excimer Laser
Excimer lasers emit cool ultraviolet light that can precisely ablate (remove) corneal tissue without burning the surrounding area.
8. In a laser pointer or DVD player, what type of laser is typically used?
a) Gas Laser
b) Dye Laser
c) Semiconductor (Diode) Laser
d) Chemical Laser
Expand Text
Answer: c) Semiconductor (Diode) Laser
These are compact, efficient, and cheap to mass-produce, making them ideal for consumer electronics and telecommunications.
9. What property refers to the fact that laser light consists of a single specific wavelength (color)?
a) Monochromaticity
b) Directionality
c) Intensity
d) Polarization
Expand Text
Answer: a) Monochromaticity
"Mono" means one and "chroma" means color. Ordinary white light is a mix of all colors; laser light is a single, pure spectral color.
10. "Holography" is a technique that creates 3D images using the interference of:
a) X-rays
b) Laser beams
c) Sound waves
d) Radio waves
Expand Text
Answer: b) Laser beams
Holography requires highly coherent light (lasers) to record the light field's phase and amplitude, creating a 3D effect.
11. The "Helium-Neon" (He-Ne) laser is a classic example of which laser type?
a) Solid-state laser
b) Gas laser
c) Liquid laser
d) Fiber laser
Expand Text
Answer: b) Gas laser
He-Ne lasers produce a continuous red beam and were widely used in early barcode scanners and school laboratories.
12. What is "Optical Pumping"?
a) Cleaning the laser lens
b) Using light (flash lamps) to excite atoms in the laser medium
c) Cooling the laser with water
d) Focusing the beam
Expand Text
Answer: b) Using light (flash lamps) to excite atoms in the laser medium
It is the process of supplying energy to the laser medium (like a Ruby crystal) to achieve population inversion.
13. "Directed Energy Weapons" (DEW) like India's KALI project primarily utilize:
a) High-energy Lasers or Microwaves
b) Sound waves
c) Nuclear missiles
d) Bullets
Expand Text
Answer: a) High-energy Lasers or Microwaves
DEWs damage targets by focusing intense energy (lasers/microwaves) on them, potentially destroying drones or missiles instantly.
14. Why are lasers preferred over LEDs for "Fiber Optic Communications"?
a) Lasers are cheaper
b) Lasers can travel longer distances with less dispersion
c) Lasers are colorful
d) LEDs cannot blink fast enough
Expand Text
Answer: b) Lasers can travel longer distances with less dispersion
Due to coherence and narrow spectral width, laser signals maintain their integrity over long kilometers of glass fiber compared to LEDs.
15. Which laser is widely used in industrial applications for cutting steel and welding?
a) CO2 Laser
b) Helium-Neon Laser
c) Laser Pointer
d) Dye Laser
Expand Text
Answer: a) CO2 Laser
Carbon Dioxide lasers are highly efficient and can produce very high continuous power (Infrared), making them perfect for heavy industry.
16. The "LIGO" experiment, which detected gravitational waves, uses massive lasers in a setup called:
a) Microscope
b) Interferometer
c) Spectrometer
d) Prism
Expand Text
Answer: b) Interferometer
It splits a laser beam into two 4km paths. When gravitational waves pass, they slightly change the path lengths, creating an interference pattern.
17. Which term describes the property of a laser beam staying narrow over long distances (low divergence)?
a) Collimation
b) Diffusion
c) Scattering
d) Reflection
Expand Text
Answer: a) Collimation
Laser light is highly collimated, meaning the rays are parallel and do not spread out (diverge) much, unlike a flashlight.
18. "Laser Cooling" is a technique used to:
a) Freeze water instantly
b) Slow down atoms to near absolute zero temperatures
c) Cool computer chips
d) Create ice cream
Expand Text
Answer: b) Slow down atoms to near absolute zero temperatures
Lasers are used to bombard atoms with photons, slowing their thermal motion (kinetic energy) to study quantum states.
19. The Apollo missions placed "Retroreflectors" on the Moon. These are used for:
a) Solar power generation
b) Lunar Laser Ranging (Measuring distance to Moon)
c) Watching Earth TV
d) Communicating with aliens
Expand Text
Answer: b) Lunar Laser Ranging (Measuring distance to Moon)
Scientists shoot lasers from Earth to these mirrors. By timing the reflection, we measure the Earth-Moon distance with millimeter precision.
20. Which class of laser is considered the most hazardous (can cause instant eye/skin damage and fire)?
a) Class 1
b) Class 2
c) Class 3R
d) Class 4
Expand Text
Answer: d) Class 4
Class 1 is safe (CD players). Class 4 includes high-power industrial and medical lasers that require strict safety goggles and protocols.
21. "Chirped Pulse Amplification" (CPA), which won the 2018 Nobel Prize, enabled:
a) Making lasers quieter
b) Creation of ultrashort, high-intensity laser pulses
c) Lasers to work underwater
d) Cheaper laser pointers
Expand Text
Answer: b) Creation of ultrashort, high-intensity laser pulses
This technique stretches a laser pulse, amplifies it, and compresses it back, allowing for powerful lasers used in eye surgery and manufacturing.
22. A "Free Electron Laser" (FEL) is unique because:
a) It uses no electricity
b) It can be tuned to emit any wavelength (tunable)
c) It is free to use
d) It occurs naturally in space
Expand Text
Answer: b) It can be tuned to emit any wavelength (tunable)
Unlike gas or crystal lasers with fixed wavelengths, FELs use a beam of electrons passing through magnets to generate light across the spectrum.
23. In a laser, the "Active Medium" is placed between two mirrors. This setup is called the:
a) Optical Resonator (Cavity)
b) Focusing Lens
c) Prism Box
d) Filter
Expand Text
Answer: a) Optical Resonator (Cavity)
The mirrors reflect light back and forth through the medium, amplifying the light with each pass before it exits as a laser beam.
24. "Barcode Scanners" in supermarkets typically use lasers to detect:
a) The weight of the product
b) The reflection pattern of black and white bars
c) The heat of the product
d) The chemical composition
Expand Text
Answer: b) The reflection pattern of black and white bars
The laser light absorbs into the black bars and reflects off the white spaces. A sensor reads this pattern to identify the product.
25. How does a Laser differ from an LED?
a) LED is brighter
b) LED emits light via spontaneous emission; Laser uses stimulated emission
c) Laser uses filament; LED uses gas
d) No difference
Expand Text
Answer: b) LED emits light via spontaneous emission; Laser uses stimulated emission
LED light is incoherent and spreads out (spontaneous). Laser light is coherent, directional, and amplified (stimulated).
Conclusion
Laser technology is a wonderful scientific discovery of the modern era that has increased the capabilities of man manifold. Today, it has an impact in every field—from medicine to missiles and from education to entertainment. If you want to make a future in the field of technology or want to get information related to it, then understanding and adopting laser technology is the need of the hour.
Online Courses, Books & Websites
| Category | Resources |
|---|---|
| Online Courses |
|
| Reference Books |
|
| Websites |
.webp)
Comments
Post a Comment