Near-field photocurrent spectroscopy of laser diode devices

Near-field optical beam-induced current (NOBIC) experiments performed on co mmercial laser diode devices are presented. NOBIC and 'macroscopic' photocu rrent data are compared and new results on edge-emitting laser devices with different waveguide architectures are analyzed. We discuss the image forma tion in these experiments, in particular the role of waveguiding and satura tion processes. Both the ground and first excited mode of the waveguide str ucture are spatially resolved. The first NOBIC images of top-emitting verti cal cavity lasers excited through the top Bragg-mirror are reported. (C) 20 00 Elsevier Science B.V. All rights reserved.