Most equipment you purchase today is classified by input power.
A 1200 watt microwave oven draws 1200 watts of power. The consumer assumes (hopefully correctly) that a 1200 watt oven heats quicker than a 1000 watt oven. How fast it heats is really how much energy is making it to the food via the microwave transmitter and that is output power. A 50 watt bulb, draws 50 watts of input power.
As a radio operator, all FCC specifications are generally input power to the final amplifier. CB radio is allow 5 watts, input to the final amplifier. You get out whatever isn’t lost (heat) in the conversion.
We don’t see that with some lasers. It may be it’s just more difficult to measure input power than output power with this type of equipment.
