Lasing in the 602-620 nm (orange-red) spectral region has been observed from R-phycoerythrin (RPE), a phycobiliprotein responsible for the >80% quantum yield of red algae. Photoexcitation of 8 μM RPE solutions in a Fabry-Pérot resonator with frequency-doubled Nd:YAG laser pulses (λp = 532 nm) yields >26 nJ of energy in ∼2.5 ns (FWHM) pulses, which corresponds to >10 W of peak power. Maximum laser emission occurs at ∼610 nm, the threshold pump energy fluence is measured to be 260 ± 15 μJ/mm2, and more than 100 longitudinal laser modes are generated when the cavity free spectral range and mirror separation are Δλ = 0.18 nm and L = 777 ± 1 μm, respectively. In combination with the known versatility of the phycobiliproteins as fluorescent tags, the biomolecular RPE laser reported here suggests its applicability to clinical assays and in situ laser imaging.
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Computer Networks and Communications