Inactivation of viruses with a very low power visible femtosecond laser

We demonstrate for the first time that, by using a visible femtosecond laser, it is effective to inactivate viruses such as bacteriophage M13 through impulsive stimulated Raman scattering. By using a very low power visible femtosecond laser having a wavelength of 425nm and a pulse width of 100fs, we show that M13 phages were inactivated when the laser power density was greater than or equal to 50MWcm^-2. The inactivation of M13 phages was determined by plaque counts and depended on the pulse width as well as power density of the excitation laser.