Patent ID: 7869469
Filing Date: 2011-01-11
Classification: G01S,Y02A

Abstract:
1. A Raman shifter, comprising: a first port for admitting, into an interior of a cell, a source beam of radiation having a first nominal wavelength; a wavelength shifting region interior of said cell containing a medium wherein radiation is shifted from said first nominal wavelength to a second nominal wavelength different than said first wavelength due to interaction of said source beam with said medium; first folding optics for folding an optical path of said source beam across said wavelength shifting region of said cell substantially free from optical overlap, said folding optics being operative for receiving said beam via a first optical path portion, defined by a first width of said source beam on said first optical path portion and a first propagation axis of said first optical path portion, and redirecting said source beam on a second optical path portion, defined by a second width of said source beam on said second optical path portion and a propagation axis of said second optical path portion, each of said first and second optical path portions extending across at least a portion of said wavelength shifting region and traversing said medium, wherein said first optical path portion is substantially free from spatial overlap with said second optical path portion inside said wavelength shifting region, wherein said first folding optics includes an interface surface defining an interface with said medium, and said first folding optics is operative for redirecting said beam such that there is a spatial offset, between a first intersection of said first propagation axis with said interface surface and a second intersection of said second propagation axis with said interface surface, that is at least about equal to the sum of one-half of the first width and one-half of the second width; and a pump source for transmitting said source beam, a seed source for transmitting a seed beam having a wavelength substantially equal to said second nominal wavelength and combining optics for combining said source beam and said seed beam for transmission into said cell via said first port.