Laser therapy, regardless of the actual laser utilized, relies upon a few key units of measurement. These measurements help select treatment protocols and monitor the dose delivered to each patient.
Refers to the average power that a laser emits during the treatment, measured in watts (W).
Ratio of “on” duration compared to “off” during one period. A period is the time it takes to complete an on-and-off cycle.
Is the does or amount that produces a therapeutic response or desired effect.
Commonly used to characterize laser output, measured in joules (J).
The energy density expresses the total amount of energy delivered per unit area, in Joules per square centimeter (J/cm2).
Unit of frequency, i. e. “pulses per second”, listed in Hz.
A unit of energy describing the work required to produce one watt of power for one second (one watt-second).
Joule cm2 (J cm2)
A unit of radiant exposure used in measuring the amount of energy per unit area of absorbing surface or per unit area of a laser beam. Also called the dose.
The maximum pulse power output of a laser and it is fixed by the laser manufacturer.
The time rate at which energy is transferred. Usually expressed in watts (joules per second); also termed radiant flux.
The intensity of the laser beam; average power divided by size of beam (“spot size”); relates to the dose.
The pulse energy is simply the total optical energy content of a pulse. Pulse mode is operation of a laser when the beam is intermittently on in fractions of a second.
Watt (W) The unit of power; equivalent to one joule per second.
Watt cm2 (W cm2)
A unit of irradiance used in measuring the amount of power per area of absorbing surface, or per cross-sectional area of a laser beam. Also called power density.
Knowing the key units of laser measurement allows us to talk in a common lanagurage about the parameters to treat patients. Please contact us to receive our ebook explaining the science of lasers.