Fig. 10: Optical setup for combining the two 780 nm Raman channels with crossed-linear-polarization and phase locking.

Approximately 10% of the combined power is diverted for phase locking while the remaining power is directed towards an acousto-optic modulator for pulsing. The combined Raman beams are coupled into the same polarization maintaining fiber with the polarizations aligned to the slow and fast axes of the fiber. PBS polarizing beam splitter, R90:T10, non-polarizing cube beam splitter; Pol. polarizer, AOM acousto-optic modulator.