button_pressed.png author=phet notes=NP
button_unpressed.png author=phet notes=NP
intensity_meter_box.png author=phet notes=NP
intensity_meter_probe.png author=phet notes=NP
knob.png author=phet notes=NP, taken from laser_knob.png
laser.png author=phet notes=NP
laser_knob.png author=phet notes=NP
protractor.png author=phet notes=SR generated with software
wave_detector_box.png author=phet notes=NP
wave_detector_probe_dark.png author=phet notes=NP
wave_detector_probe_light.png author=phet notes=NP
