Spatial mode control of radiation generated by frequency difference in periodically poled crystals - art. no. 113901

We demonstrate the possibility to control the spatial mode of a narrow-line width, continuous-wave, infrared radiation beam generated by difference fre quency in a periodically poled crystal. This can be achieved by acting dire ctly on a few experimental parameters. We show that hollow beams can be gen erated. A numerical routine has been developed and results agree with exper imental observations, without requiring any free parameters. The relevance of these results for high-resolution spectroscopy and atom manipulation is discussed.