To measure a convex mirror, a reference beam and a measurement beam are both
provided
through a single optical fiber. A positive auxiliary lens is placed in the system
to give a converging wavefront onto the convex mirror under test. A measurement
is taken that includes the aberrations of the convex mirror as well as the errors
due to two transmissions through the positive auxiliary lens. A second measurement
provides the information to eliminate this error. A negative lens can also be measured
in a similar way. Again, there are two measurement set-ups. A reference beam is
provided from a first optical fiber and a measurement beam is provided from a second
optical fiber. A positive auxiliary lens is placed in the system to provide a converging
wavefront from the reference beam onto the negative lens under test. The measurement
beam is combined with the reference wavefront and is analyzed by standard methods.
This measurement includes the aberrations of the negative lens, as well as the
errors due to a single transmission through the positive auxiliary lens. A second
measurement provides the information to eliminate this error.
