Near-field scanning optical microscopy (NSOM) can image the optical emission and absorption properties of materials and devices at resolutions typically l/10. This approximately 5-fold increase in resolution over conventional far-field microscopy comes at a significant cost in light gathering ability and hence imaging speed, limiting the application of NSOM. Near-field imaging relies on maintaining near-surface scanning. It is thus ideally suited to collect evanescent optical fields which do not propagate into the far-field, and cannot be measured by conventional microscopy. In addition, the sub-wavelength aperture defines a very small depth of field, allowing high resolution vertical sectioning unobtainable with far-field optics. In this talk, we describe our recent efforts in using NSOM to monitor evanescent fields and spontaneous emission to determine internal optical intensity maps in photonic materials and devices. The spatial modes inside a one-dimensional photonic band gap device operating in the near-IR have been imaged using NSOM. Our results show large scattering at the transition between waveguide modes and lattice modes, increased scattering for wavelengths within the stop band, and the presence of a narrow-band, localized mode of a photonic defect state located near the center of the device. In a different set of experiments we have mapped the internal pump intensity distribution of an optically pumped vertical-cavity surface-emitting laser. Spontaneous emission from quantum wells placed throughout the distributed Bragg reflectors is correlated to the pump intensity. The emission is monitored along the cleaved edge using the high spatial resolution and shallow depth of field provided by NSOM. Our results show a distinct buildup of optical intensity between the mirror stacks. Low-temperature NSOM has been used to spatially and spectroscopically map the emission from individual quantum dots in self-assembled structures. We will discuss their pressure dependence and spectral and spatial correlations in collection mode imaging. The close correlation in both energy and spatial position of neighboring dots could be due to the influence of atomic step edges on the size of islands during growth. Finally, recent results on excitation spectroscopy will be mentioned.