Characterization Techniques

This chapter of LED Characterization describes comprehensively why characterization is necessary, what types of characterization are required and how they are carried out, and how engineers should interpret obtained data. Starting with light-output total-flux measurement methods using an integrating sphere combined with a spectrometer (Sect. 2.2), Sect. 2.3 discusses step-by-step data reduction from spectral data to commonly-seen figure-of-merit (FOM) quantities of radiometry, photometry, and colorimetry. Following is Sect. 2.4, providing a streamlined mathematical process of efficiency breakdown analysis with supplemental Sect. 2.5. Section 2.6 is to introduce other quantities than those related to the integrating sphere measurement. Sections 2.7-2.10 are predominantly dedicated to discussions on electrical, thermal, and reliability tests that are employed in industry.