The tutorial is dealing with thermal and electroluminescent emission of light as well as the absorption phenomena of materials for electronic devices. Based upon an inspection of the principles, the mechanisms of techniques like lock-in thermography, photon emission microscopy or the laser stimulation varieties will be derived. Included is a check of the localization potential when evaluating the lock in phase signal for delay information. A special feature addresses the signal acquisition through bulk silicon and spectral issues. After talking about the wide application range of optical interaction with electronic devices for localization of device (mal)functions, a special focus is set onto photon emission. A chapter looks at different operating modes of various electronic devices in static or time resolved mode and their respective photon emission specifics. Another chapter handles the selection of detectors and other set up topics. Last but not least aspects of nanoscale technology specifics as well as the respective resolution requirements will be highlighted.