Scanning Laser

A laser having a time-varying direction, origin, or pattern of propagation with respect to a stationary frame of reference.

Semiconductor Laser

A type of laser which produces its output from semiconductor materials such as GaAs.

Solid Angle

The ratio of the area on the surface of a sphere to the square of the radius of that sphere. It is expressed in steradians (sr).

Spectral Response

The response of a device or material to monochromatic light as a function of wavelength.

Spot Size

The mathematical measurement of the radius of the laser beam.


The ability of a laser system to resist changes in its operating characteristics. Temperature, electrical, dimensional, and power stability are included.

Stimulated Emission

When an atom, ion, or molecule capable of lasing is excited to a higher energy level by an electric charge or other means, it will spontaneously emit a photon as it decays to the normal ground state. If that photon passes near another atom of the same energy, the second atom will be stimulated to emit a photon.