Neodymium-YAG Laser

An example of a solid-state laser, the neodymium-YAG uses the Nd³⁺ ion to dope the yttrium-aluminum-garnet (YAG) host crystal to produce the triplet geometry which makes population inversion possible. Neodymium-YAG lasers have become very important because they can be used to produce high powers. Such lasers have been constructed to produce over a kilowatt of continuous laser power at 1065 nm and can achieve extremely high powers in a pulsed mode.

Neodymium-YAG lasers are used in pulse mode in laser oscillators for the production of a series of very short pulses for research with femtosecond time resolution.

Neodymium-Glass Lasers

Neodymium glass lasers have emerged as the design choice for research in laser-initiated thermonuclear fusion. These pulsed lasers generate pulses as short as 10^-12 seconds with peak powers of 10⁹ kilowatts.

Ruby Laser

The ruby laser is the first type of laser actually constructed, first demonstrated in 1960 by T. H. Maiman. The ruby mineral (corundum) is aluminum oxide with a small amount (about 0.05%) of chromium which gives it its characteristic pink or red color by absorbing green and blue light.

The ruby laser is used as a pulsed laser, producing red light at 694.3 nm. After receiving a pumping flash from the flash tube, the laser light emerges for as long as the excited atoms persist in the ruby rod, which is typically about a millisecond.

A pulsed ruby laser was used for the famous laser ranging experiment which was conducted with a corner reflector placed on the Moon by the Apollo astronauts. This determined the distance to the Moon with an accuracy of about 15 cm.

Pumping Levels for Ruby Laser

Ruby Laser and Flash Tube