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

A pulse repetition frequency above which the laser is considered to operate as a CW laser. [box]Example:  For a short (0.25 s to 10 s) unintentional exposure to nanoseconds (or longer) pulses, the Critical Frequency is 55 kilohertz (kHz) for wavelengths between 400 nanometers (nm) to 1050 nm and 20 kHz for wavelengths between 1050 nm to 1400 nm.[/box]

Maximum flow of electric force in a conductor; in a laser, the point at which further electrical charge will not increase lasing action.