1. A method for optically communicating, from a user to a laser tracker, a command to control operation of the laser tracker with steps comprising: providing a rule of correspondence between each of a plurality of commands and each of a plurality of temporal patterns; selecting by the user a first command from among the plurality of commands; projecting a first light from the laser tracker to a retroreflector; reflecting a second light from the retroreflector, the second light being a portion of the first light; obtaining first sensed data by sensing a third light imaged onto a photosensitive array, the third light being a portion of the second light; creating by the user, between a first time and a second time, a first temporal pattern, the first temporal pattern including at least a decrease in optical power of the third light followed by an increase in the optical power of the third light, the first temporal pattern corresponding to the first command; determining the first command based at least in part on processing the first sensed data according to the rule of correspondence; and executing the first command with the laser tracker.