Brightness limitations in integrated lighting systems

In this paper, the foundations of radiometry and photometry, based on Second Principle of Thermodynamics are discussed, in terms of brightness (luminance), and etendue (Lagrange invariant) limitations of integrated lighting systems. In such a case, the brightness is defined as phase-space-density, and other radiometric/photometric quantities such as emittance, exitance, or irradiance/illuminance, power/flux, and radiant/luminant intensity, are also discussed, including examples of integrated lighting systems. Also, technologic progress at Luminit is reviewed, including 3D-microreplication of new non-diffuser microscopic structures by roll-to-roll web technology.