Collimation testing based on self-imaging

ROBERTO TORROBA; NESTOR BOLOGNINI; MYRIAN TEBALDI; ALBERTO TAGLIAFERRI

Tandil

Conferencia; 4th Iberoamerican meeting on Optics and 7th Latin American Meeting on Optics, Lasers and their Applications,; 2001

Comite Territorial Optica de Argentina

It is proposed a technique to test the collimation status of a beam. The testing combines a moire beating technique with a digital technique. A self-image of the grating produced by a collimated beam is stored in the memory of the frame grabber. When a decollimation of the laser beam exists, the self-image period is modified. The digital subtraction between both selfimage gratings produce a beating pattern. The beating moire fringe spacing is related to the decollimation degree of the illuminating beam. The validity ofthe technique is verified experimentally by using lenses ofvarious focal lengths