Optical characterization using local probes with submicrometric spatial resolution is very useful for many problems concerning compound semiconductors and devices. In particular, micro-Raman spectroscopy and cathodoluminescence spectrum imaging are very powerful analytical techniques that manage good signal/noise ratios allowing to acquire images including spectral information and slightly submicrometric spatial resolution in a short time. The main analytical and spatial resolution aspects concerning both techniques are addressed. Several examples are presented in order to illustrate the capabilities of micro-Raman and cathodoluminescence spectrum imaging for the characterization of compound semiconductors and the devices based on them. (c) 2006 Elsevier B.V. All rights reserved.