Patent attributes
A Raman shifter is provided with improved optical efficiency and robustness, particularly for high power applications. In one embodiment, a source system (100) includes a source pump laser (102) and a seed laser (104). Beams from the pump laser (102) and seed laser (104) combine for transmission into a Raman cell (112). Folding optics define a multi-pass pathway through the Raman cell (112). Such folding optics may include an internal reflectance element. An entry window into the Raman cell, an exit window from the Raman cell, and the internal reflectance elements include surfaces disposed at a Brewster angle relative to the incident beam. The Raman cell medium is circulated in a direction transverse to the beam pathways through the cell. In this manner, improved optical efficiency and robustness is achieved as well as improved performance over a significant wavelength band.
