Lecture

Gain saturation

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Description

This lecture covers the concept of gain saturation in laser systems, where the stimulated emission cannot be neglected above the threshold, illustrated with examples like the Ruby laser and the 3-level system. It also discusses the rate equations for photo and photon interactions, emphasizing the importance of maintaining a balance between pumping and emission processes. The lecture delves into the dynamics of atoms in different energy levels and the factors influencing laser output power, such as diode pumping and output coupling efficiency.

Official source

Ontological neighbourhood

Physics

Optics: Lasers

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A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word laser is an anacronym that originated as an acronym for light amplification by stimulated emission of radiation. The first laser was built in 1960 by Theodore Maiman at Hughes Research Laboratories, based on theoretical work by Charles H. Townes and Arthur Leonard Schawlow. A laser differs from other sources of light in that it emits light that is coherent.

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A helium–neon laser or He-Ne laser is a type of gas laser whose high energetic medium gain medium consists of a mixture of ratio(between 5:1 and 20:1) of helium and neon at a total pressure of about 1 torr inside of a small electrical discharge. The best-known and most widely used He-Ne laser operates at a wavelength of 632.8 nm, in the red part of the visible spectrum. The first He-Ne lasers emitted infrared at 1150 nm, and were the first gas lasers and the first lasers with continuous wave output.

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