Engineering Physics II - Laser and Fibre Optics

LASER Fundamentals

• LASER stands for Light Amplification by Stimulated Emission of Radiation.

Laser Components and Mechanisms

• The essential component of a laser system responsible for establishing population inversion and stimulated emission is the gain medium.
• Albert Einstein first put forward the basic scientific principle behind a laser.
• The pumping mechanism in a laser system is responsible for achieving population inversion.

Laser System Functions

• The function of the optical resonator in a laser system is to provide feedback, allowing the stimulated emission to build up and create a coherent beam of light.

Laser Development and History

• The first pulsed laser was developed in 1960.

Laser Types and Characteristics

• The primary pumping mechanism in a gas laser is electrical discharge.
• The Ruby Laser exemplifies a solid-state laser system.
• The main active center in the He-Ne laser is Ne (neon).
• The He-Ne laser utilizes a three-level energy system.

Laser Physics and Processes

• Stimulated emission is initiated by the presence of photons in the resonator.
• Lasing ceases and the laser becomes inactive when the population inversion is lost.
• In a solid-state laser, population inversion is primarily achieved through optical pumping.
• The Ruby crystal is made of aluminum oxide (Al2O3) with chromium impurities.
• The Ruby laser has a relatively inefficient energy conversion of 0.1 to 1%.
• The depopulation of the metastable state E2 in a Ruby Laser is caused by spontaneous emission and non-radiative decay.

Test your knowledge of Chapter 4: Laser and Fibre Optics in Engineering Physics II. Learn about the acronym LASER, the scientific principle behind lasers, and the development of the first laser in 1960.