Angle of beam spread, measured in (milli)radians. Can be approximated for small angle by the ratio of the beam diameter to the distance from the laser aperture.

The emission intensity of the laser beam radiation measured as a function of the angle. The value is normally measured from the full width at half maximum (FWHM) of the emission intensity. Such measurement is giving in two different directions: one perpendicular to the p-n junction and the other parallel to the p-n junction.

Angle of beam spread measured in radians or milliradians (1 milliradian = 3.4 minutes-of-arc or approximately 1 mil). For small angles where the cord is approximately equal to the arc, the beam divergence can be closely approximated by the ratio of the cord length (beam diameter) divided by the distance (range) from the laser aperture.