We present an overview of a cross‐sectional scanning microphotoluminescence technique that is used to examine various buried‐layer semiconductor structures for which traditional surface‐normal techniques cannot yield sufficient information or must be coupled with time‐consuming and painstaking processes such as wet etching. This technique has a wide range of applications; two—defect‐driven interdiffusion in quantum wells and the modification of spontaneous emission from quantum wells in vertical‐cavity surface‐emitting lasers (VCSELs)—are discussed here. The data obtained using this method can be used to distinguish emission spectra from quantum wells as little as one micrometer apart in depth and a few nanometers different in wavelength. The comparison of normal incidence with cross‐sectional data from VCSELs can be used to more effectively optimize the match between cavity resonance and quantum well emission in high‐Qdevices. ©1995 American Institute of Physics.