An instrument which measures the energy, usually as heat generated by absorption of the laser beam.

Carbon Dioxide

Molecule used as a laser medium. Emits far infrared energy at 10,600 nm (10.6 micrometers).


A negatively charged electrical element providing electrons for an electrical discharge.

Closed Installation

Any location where lasers are used which will be closed to unprotected personnel during laser operation.

CO2 Laser

A widely used laser in which the primary lasing medium is carbon dioxide gas. The output wavelength is 10.6 micrometers in the far infrared spectrum. It can be operated in either CW or pulsed.


A term describing light as waves which are in phase in both time and space. Monochromaticity and low divergence are two properties of coherent light.

Collimated Light

Light rays that are parallel. Collimated light is emitted by many lasers. Diverging light may be collimated by a lens or other device.


Ability of the laser beam to not spread significantly (low divergence) with distance.

Combiner Mirror

The mirror in a laser which combines two or more wavelengths into a coaxial beam.

Continuous Mode

The duration of laser exposure is controlled by the user (by foot or hand switch).

Continuous Wave (CW)

Constant, steady-state delivery of laser power.


The bending of light rays toward each other, as by a positive (convex) lens.

Corrected Lens

A compound lens that is made measurably free of aberrations through the careful selection of its dimensions and materials.


A solid with a regular array of atoms. Sapphire (Ruby Laser) and YAG (Nd:YAG laser) are two crystalline materials used as laser sources.