Enhancement of the lasing efficiency of vitamin B 2 in a highly polar organic solvent via DNA-lipid complex.

We experimentally demonstrated a green liquid laser at the wavelength of 570 nm, utilizing the optical gain of vitamin B2 in a highly polar organic solvent, and proposed an efficient method to enhance its lasing efficiency by adding DNA-lipid complex (DNA-CTMA) in the solution. Optical properties of vitamin B2 in the hexafluoro-2-propanol solvents were investigated by adding various amounts of DNA-CTMA in terms of the UV-visible absorbance, the visible emission, and the fluorescence lifetime. A Fabry-Perot cavity was built to obtain the laser oscillation at 570 nm using a pulsed pump source at the wavelength of 450 nm, 5 ns pulse duration, and 10 Hz repetition rate. By adding DNA-CTMA, both the output power and slope efficiency were enhanced along with a significant reduction of the lasing threshold pump power. The proposed scheme could open new potential for highly efficient biolasers.