The design and operation of a number of techniques in near field optical microscopy are described. Specific attention is paid to the three modalities of polarization, interference contrast, and photoluminescence imaging. By premodulating the polarization state of the sample beam, pure, linear, polarizing microscopy is performed. In addition, polarization anomalies are observed in the focal plane of a high numerical aperture lens. Amplitude and phase contrast imaging is performed in a feedback stabilized Mach-Zehnder interferometer. Magneto-optically induced polarization shifts are detected interferometrically, resulting in linear sensitivity. Localized photoluminescence is induced in porous silicon, and the results are correlated with the topography of the sample.