Beam profile shaping for laser radars that use detector arrays

The beam shaper developed shapes the transmit beam of a CO2 laser radar that uses a linear detector array. It consists of a diffraction grating and an anamorphic prism beam compressor, and produces a stretched profile that efficiently and uniformly illuminates the far-field footprint of the detector array. The diffraction grating phase modulates the near field of the laser beam to generate a far-field flattop intensity profile, whereas the compressor produces the necessary profile eccentricity. Conversion efficiencies in the 70-90% range have been achieved.