Bio-optimized energy transfer in densely packed fluorescent protein enables near-maximal luminescence and solid-state lasers

This work was supported by the US National Science Foundation (ECCS- 1101947), National Institutes of Health (P41EB015903, R21EB013761), Department of Defense (FA9550-11-1-0331), and the Korea National Research Foundation (R31-2008-000-10071-0). M.C.G. acknowledges support from the Bullock-Wellman Fellowship, the Daimler and Benz Fellowship and the Marie Curie Career Integration Grant (PCIG12-GA-2012-334407).Bioluminescent organisms are likely to have an evolutionary drive towards high radiance. As such, bio-optimized materials derived from them hold great promise for photonic applications. Here, we show that biologically produced fluorescent proteins retain their high brightness even at the maximum density in solid state through a special molecular structure that provides optimal balance between high protein concentration and low resonance energy transfer self-quenching. Dried films of ​green fluorescent protein show low fluorescence quenching (−7 dB) and support strong optical amplification (gnet=22 cm−1; 96 dB cm−1). Using these properties, we demonstrate vertical cavity surface emitting micro-lasers with low threshold (