High-power near-CW Raman lasing in mm-sized glass disks

Abstract

We experimentally demonstrate Raman lasing in a mm-sized CaF2 disk, with an optical power output of the first Stokes sideband exceeding 100 mW in a near-continuous wave (CW) operation. The pump beam at a wavelength of 1.06 μ m is coupled to the whispering gallery modes of the disk with the use of a tapered glass fiber. With the pump beam coupled to one of the resonator modes, we observe the generation of the first and the second Stokes sidebands at wavelengths of 1.1 μ m and 1.14 μ m, respectively. The conversion efficiency from the pump laser beam to the generated sidebands is ∼10%. These results open up the prospect of using such mm-sized disks as compact, highly efficient ultrafast modulators with modulation frequencies as high as 10 THz.