ACHROMATIC 3-WAVE (OR MORE) LATERAL SHEARING INTERFEROMETER

A new kind of lateral shearing interferometer, called the three-wave l ateral shearing interferometer, was previously described [Appl. Opt. 3 2, 6242 (1993)]. As this instrument was monochromatic and its usable l ight efficiency was poor, the proposed setup was well suited only for a class of wave-front sensing problems, such as optical testing, in wh ich the source can be easily adapted. A new achromatic setup adapted t o low light level applications is presented. Three replicas of the ana lyzed wave front are obtained by Fourier filtering of the orders diffr acted by a microlens array. An important feature of these new devices is their great similarity to another class of wave-front sensors based on the Hartmann test. (C) 1995 Optical Society of America.