Stimulated Raman red-light generation by acetone as a perspective source for photodynamic therapy applications

We report on a new source of coherent red-light with perspective applications in laser photodynamic therapy. The red light is generated through stimulated Raman scattering (SRS) process by acetone of a frequency-doubled Nd:YAG nanosecond laser radiation (532 nm). The Stokes transition is found at 630 nm and with spectral line narrowing similar to the pump one. When pumping using the radiation from a Rhodamine-6G Dye laser (560 - 575 nm), tuning between 640 and 670 nm is demonstrated. Conversion efficiencies up to 50% are reported.