Wideband Raman comb generation using liquid hydrogen droplet

Summary form only given. Liquid hydrogen is the simplest molecular liquid known as a quantum liquid. The unique feature of liquid hydrogen is that the H/sub 2/ molecules consisting of the liquid have well-defined vibrational and rotational quantum states as free molecules. Here, we treat the liquid hydrogen as a nonlinear Raman medium for droplet nonlinear optics and carry out stimulated Raman scattering (SRS) experiments using the whispering-gallery (WG) modes in the droplet. We show that, by pumping at ultraviolet wavelength, the SRS generates many multiple-order Stokes series through vibrational and rotational coherences covering whole ultra violet-visible region from 200 nm to 1,000 nm, which may turn out as a super wideband optical comb generator.