Raman laser
AssigneeGEC Ferranti Defence Systems Limited
InventorStewart T. Whittley
Life of this patent
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Abstract
This invention provides a Raman laser wherein a light beam from a laser source (1) passes through a first chamber (3) and experiences Raman scattering, and then passes through a second chamber (9) and experiences further Raman scattering, such that the output of the Raman laser is frequency shifted. The first and second chambers may be distinct from each other enabling different types and pressures of gases to be utilised, or may be one and the same (20) providing a particularly compact arrangement. A Raman laser in accordance with the invention is particularly suitable for the production of light consisting of multiple rotational Raman orders, and particular embodiments enable frequency switching to be achieved and also provides arrangements which reduce the problems of boresight stability and gas circulation encountered with previous designs.
Claims24
A Raman laser comprising a first and a second chamber each containing a Raman active gas, wherein the first chamber is arranged to receive an incident coherent pump beam which experiences forward Raman scattering on passing through the first chamber, and wherein the second chamber is arranged to receive an output beam from the first chamber which experiences further forward Raman scattering on passing through the second chamber, the Raman laser further comprising a steering optic by which the pump beam entering the first chamber, and the Raman shifted beam exiting the second chamber are deflected.
A Raman laser comprising a first and second chamber each containing a Raman active gas, the first chamber being arranged to receive a coherent pump beam which experiences forward Raman scattering on passing through the first chamber, and the second chamber being arranged to receive an output beam from the first chamber which experiences further forward Raman scattering on passing through the second chamber, the Raman laser further comprising a filter between the first and second chambers which is transmissive to rotationally scattered Raman radiation and the pump beam, and is substantially non-transmissive to vibrationally scattered Raman radiation.
A Raman laser comprising a first and second chamber each containing a Raman active gas, the first chamber being arranged to receive a coherent pump beam which experiences forward Raman scattering on passing through the first chamber, and the second chamber being arranged to receive an output from the first chamber which experiences further forward Raman scattering on passing through the second chamber, the Raman laser further comprising means for circularly polarising the pump beam incident on the first chamber, and altering the polarisation of the beam emerging from the first chamber such that it enters the second chamber elliptically polarised.
Dependencies are inferred from the claim text.