We study the problem of separating E and B modes in interferometric
observations of the polarization of the cosmic microwave background. The E and
B band powers and their mixings are measured from both single-dish and
interferometric mock observations using the quadratic estimator of the maximum
likelihood analysis. We find that the interferometer can separate E and B modes
in a single-pointing measurement and is thus well suited for detecting the
faint lensing induced and gravity-wave induced B modes. In mosaicking
observation, compared to the single dish, the interferometer is in general more
efficient in separating E and B modes, and for high signal-to-noise per pixel
it needs about three times fewer pixels to measure extremely blue polarization
power spectra.Comment: 21 pages, 11 figures, ApJ in pres