Laser power is delivered at normal intensities or powers to the end of a laser guide such as an articulated arm from a laser console where the beam enters an attached attenuating unit. Inside the attenuator, the beam encounters a dual wavelength beam splitter that transmits an attenuated beam at, for example, 20 times reduction of power. The attenuated beam may be delivered to an area of medical treatment. The beam splitter is also reflective and reflects the remaining power to a power sensor where the thermal energy is absorbed and measured. The power of the attenuated beam is related to the power of the measured reflected beam. The beam splitter is coated to allow maximum transmission of a visible guide beam that always travels coaxially to the operating laser energy being attenuated. A signal from the power sensor is provided to a preferably battery powered read-out device that provides the surgeon with real time accurate readings of delivered power.