Eur. Phys. J. Appl. Phys. 27, 451-454 (2004)
https://doi.org/10.1051/epjap:2004098

Simultaneous quantitative determination of strain and defect profiles within the active region along high-power diode laser bars by micro-photocurrent mapping

¹ Max-Born Institut für nichtlineare Optik und Kurzzeitspektroskopie, Max Born Strasse 2A, 12489 Berlin, Germany
² THALES Research & Technology, Domaine de Corbeville, 91404 Orsay Cedex, France

Corresponding author: gerhardt@mbi-berlin.de

Received: 14 July 2003
Accepted: 9 December 2003
Published online: 15 July 2004

Abstract

We present microscopically-resolved photocurrent spectroscopy as a new powerful analytical tool for the simultaneous detection of packaging-induced strain and defects in GaAs-based high-power laser diode arrays (cm-bars). Using the Fourier-transform (FT) technique we measure photocurrent (PC) spectra with a high spatial resolution of better than 50 μm at the active layer of the device. By analyzing this data, spatially resolved distributions of strain as well as of defects are obtained. So far, PC measurements at cm-bars have only provided an overview of the distribution of strain and defects in the device on an emitter-by-emitter scale. The high spatial resolution now allows examination of the distribution of strain and defects even within one single emitter. This is essential for obtaining insights into device failure mechanisms and also makes a substantial contribution for improving device performance and reliability.