A method and system of operating a laser device includes utilizing an integral power-regulation sensor of the laser device to detect energy back reflected from an object of interest and then using the detected signal as a basis for determining a characteristic related to the object of interest. In the preferred embodiment, the determined characteristic is the position of the beam focus relative to a surface of the object. Also in the preferred embodiment, the integral power-regulation sensor is disconnected from power-regulation circuitry during the focusing operation. Interaction of the back reflected energy and the outgoing beam can be reduced by introducing beam rotation, such as by providing a quarter-wave plate along the beam path. Focusing sensitivity can be increased by locating reflective targets over the surface and by executing AC measurements to filter DC components from the signal.