| CPC G01M 11/0207 (2013.01) | 20 Claims | 

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               1. A system for measuring a satellite ghost efficiency of a diffractive lens, comprising: 
            a light source configured to output a first probing beam; 
                a beam tweaking assembly disposed between the light source and the diffractive lens, and configured to convert the first probing beam into a second probing beam that is a non-collimated beam, the diffractive lens diffracting the second probing beam into a plurality of diffracted beams including a first diffracted beam of a parent diffraction order and a second diffracted beam of a satellite ghost diffraction order, wherein the beam tweaking assembly includes one or more optical lenses, and an optical power of the beam tweaking assembly is adjustable; and 
                a detector configured to generate a beam spot pattern including a first beam spot corresponding to the first diffracted beam and a second beam spot corresponding to the second diffracted beam. 
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