LASER HOW DOES IT WORK ? LASER LIGHT PRINCIPLES OF OPERATION DIFFERENCE WITH COMMON LIGHT

Summary

This video explains the science behind lasers, beginning with how ordinary light sources emit multiple wavelengths in all directions, while lasers produce light of a single wavelength, all in sync and traveling in one direction. The first laser was created using a ruby rod, mirrors, and a xenon flash tube, which excites electrons in chromium atoms to emit photons. These photons amplify the laser light as they reflect between mirrors. The unique properties of laser light, such as its purity and intensity, have made lasers invaluable in industries like research, medicine, and manufacturing.

Takeaways

• 😀 A typical light source emits a wide range of wavelengths in all directions.
• 😀 Lasers generate light waves of a single wavelength, all in step with each other, and all traveling in the same direction.
• 😀 Laser light is pure in color and extremely intense due to its coherent nature.
• 😀 The first laser was created using a ruby rod, mirrors, and a xenon flash tube.
• 😀 Intense light from the flash tube excites electrons in the ruby's chromium atoms, raising them to higher energy levels.
• 😀 When electrons fall back to lower energy levels, photons (particles of light) are emitted.
• 😀 Photons emitted from chromium atoms can stimulate other excited atoms, causing them to emit identical photons.
• 😀 Laser light is amplified as photons bounce between mirrors, intensifying the reactions.
• 😀 The laser light exits through a partially silvered mirror, allowing a focused beam of light to emerge.
• 😀 Lasers have become crucial tools in various industries, including research and medicine, due to their powerful and precise light output.

Q & A

What is the main difference between an ordinary light source and a laser?

An ordinary light source emits light in many different wavelengths and in all directions, whereas a laser emits light of a single wavelength, all in step with each other, and all traveling in the same direction.

Why is laser light considered pure in color and intense?

Laser light is pure in color because it consists of a single wavelength, and it is intense due to all the light waves being in phase with each other and traveling in the same direction.

How was the first laser created?

The first laser was created using a ruby rod, mirrors, and a xenon flash tube. Intense light from the flash tube excited electrons in the chromium atoms of the ruby, initiating the laser process.

What role do the chromium atoms in the ruby play in the laser process?

The chromium atoms in the ruby absorb energy from the flash tube, which excites their electrons to higher energy levels. As these electrons fall back to lower levels, photons of light are emitted, contributing to the laser beam.

What happens when photons from chromium atoms strike other excited atoms?

When photons from chromium atoms strike other excited atoms, they stimulate the emission of new photons that are identical to the first, helping amplify the laser light.

How is laser light amplified in the system described?

Laser light is amplified as photons travel back and forth between mirrors, intensifying the reactions and increasing the number of photons emitted in phase.

Where does the laser light exit from the system?

The laser light exits the system through a partially silvered mirror, allowing a controlled amount of light to be emitted.

Why are lasers valuable in various fields like industry, research, and medicine?

Lasers are invaluable in these fields due to their ability to produce powerful, focused beams of light, which can be precisely controlled and used for cutting, measurement, diagnostics, and various treatments.

What is the significance of the photons being identical in the laser process?

The fact that the photons are identical ensures that the laser light is coherent, meaning all the light waves are in phase with each other, which contributes to the high intensity and focus of the beam.

What happens to the electrons in the chromium atoms when they fall back to lower energy levels?

When electrons in the chromium atoms fall back to lower energy levels, they release energy in the form of photons, which are crucial for generating the laser light.