Measuring the angles and pyramidal error of high-precision prisms UsN b&aue
p( *3U[1
High-precision prisms, having maximum angle tolerances t5h_Q92N
of 1 to 3 arcsec, find increasing application in optical metrology. fXe-U='
Reported interferometric techniques for measuring `Ny8u")=
the wedge angles of such prisms achieve a precision of up 2r, '4%G
to 0.1 arcsec ~Ref. 1!, while noninterferometric techniques - (1\ `g07
have a precision of up to 2 arcsec ~Ref. 2!. Reported noninterferometric &J$5+"/;X
methods have made use of goniometers,2 Q=E@i9c9
spectrometers,3 master prisms,4,5 and collimators.6 However, 4& e@>
in the literature there are few reported methods for * a!!(cZZ
measuring the pyramidal error, and the majority rely on dH|^\IQ
visual observation,2,7,8 by which it is only possible to measure RWFf-VA?
pyramidal errors to the order of 1 arcmin ~Ref. 8!. "\ ;wMR{
In the new arrangement presented here, one can measure <R>z;2c
the prism angle and the pyramidal error separately or in \F~Cbj+'Nu
combination. This is possible because the measurements S:/ RYT"
are made simultaneously but with different techniques.
