Perforated plate lens for millimeter quasi-optical systems

A perforated plate lens operating in the 2.5-mm wavelength range designed to carry out transformation of a Gaussian beam to produce a focused beam of small dimensions is described. Truncation of the incident beam by the lens at the -20 dB relative power level is shown both theoretically and experimentally to allow a highly Gaussian power distribution of the focused radiation. The waist radius and location of the output beam of the perforated plate lens agree well with the predictions of Gaussian beam transformation formulas over the measured 12% fractional bandwidth.<
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