A wearable display device, comprising: left and right display lens systems configured for augmented reality imaging; left and right imaging units of the respective left and right display lens systems configured to generate an augmented reality image, at least one of the left and right imaging units comprising: an emitter structure having one or more light sources configured to emit light; one or more optical elements configured to direct the light along a light path in the imaging unit; a display optic located in the light path; an electrically alterable scanning optical element configured to receive the light from the one or more optical elements and direct the light to the display optic, the electrically alterable scanning optical element being configured to scan in at least one dimension to direct the light through an imaging optic that directs the light into the display optic; a calibration light sensor for receiving a portion of the light from one of the one or more optical elements, the calibration light sensor being located at a point along the light path between the emitter structure and the electrically alterable scanning optical element; and a calibration control system configured to receive sensor data from the calibration light sensor, the sensor data corresponding to a power level of light generated by the light source; wherein the calibration control system is configured to conduct a process of calibrating a monitor sensor that monitors light output from the light source, the calibration control system being configured to conduct the calibration process using the sensor data; and wherein the light source is a laser diode and the monitor sensor is a photodiode configured to receive light emitted from a back facet of the laser diode. left and right display lens systems configured for augmented reality imaging; left and right imaging units of the respective left and right display lens systems configured to generate an augmented reality image, at least one of the left and right imaging units comprising: an emitter structure having one or more light sources configured to emit light; one or more optical elements configured to direct the light along a light path in the imaging unit; a display optic located in the light path; an electrically alterable scanning optical element configured to receive the light from the one or more optical elements and direct the light to the display optic, the electrically alterable scanning optical element being configured to scan in at least one dimension to direct the light through an imaging optic that directs the light into the display optic; a calibration light sensor for receiving a portion of the light from one of the one or more optical elements, the calibration light sensor being located at a point along the light path between the emitter structure and the electrically alterable scanning optical element; and a calibration control system configured to receive sensor data from the calibration light sensor, the sensor data corresponding to a power level of light generated by the light source; wherein the calibration control system is configured to conduct a process of calibrating a monitor sensor that monitors light output from the light source, the calibration control system being configured to conduct the calibration process using the sensor data; and wherein the light source is a laser diode and the monitor sensor is a photodiode configured to receive light emitted from a back facet of the laser diode. an emitter structure having one or more light sources configured to emit light; one or more optical elements configured to direct the light along a light path in the imaging unit; a display optic located in the light path; an electrically alterable scanning optical element configured to receive the light from the one or more optical elements and direct the light to the display optic, the electrically alterable scanning optical element being configured to scan in at least one dimension to direct the light through an imaging optic that directs the light into the display optic; a calibration light sensor for receiving a portion of the light from one of the one or more optical elements, the calibration light sensor being located at a point along the light path between the emitter structure and the electrically alterable scanning optical element; and a calibration control system configured to receive sensor data from the calibration light sensor, the sensor data corresponding to a power level of light generated by the light source; wherein the calibration control system is configured to conduct a process of calibrating a monitor sensor that monitors light output from the light source, the calibration control system being configured to conduct the calibration process using the sensor data; and wherein the light source is a laser diode and the monitor sensor is a photodiode configured to receive light emitted from a back facet of the laser diode.