First results are presented demonstrating the feasibility of using an integrated optics array of Mach–Zehnder dielectric‐waveguide interferometers to measure the phase and amplitude across an optical wave front. The interferometers are formed from single‐mode waveguides produced by Ti diffusion into LiNbO3. The spacing between the arms of the interferometer is 20 &mgr;m. The phase difference &fgr; between the optical waves incident on the two interferometers arms is measured and compared with theory. The excellent and reproducible agreement between experiment and theory over a number of interferometers suggests that the accuracy of the wave front measurement sensor should be attractively high, limited only by signal statistics and noise considerations. As example, a sensor design is given for which the rms deviation (1&sgr;) in the value of &fgr; is less than 4.5° (the rms deviation in the optical path difference is less than &lgr;/80).