A process well-suited to lasers which involves hardening metal by heating it to the critical temperature for transformation, quenching it, and solidifying it with uniform distribution of its carbon content.

In optics, the passage of radiant energy (light) through a medium.

The ratio of transmitted radiant energy to incident radiant energy, or the fraction of light that passes through a medium.

The amount of visible light usable to the eye that passes through a filter. As a rule of thumb, as optical density increases, visible light transmission decreases — but not always. Also (same as) Visible Light Transmission.

Abbreviated TEM. The cross-sectional shape of the working laser beam. An infinite number of shapes can be produced, but only a relatively small number are needed for industrial applications. In general, the higher the TEM, the coarser the focusing.