Abstract

As diode arrays for pumping Nd lasers become more prevalent, the need to characterize their performance has increased. A technique for measuring the beam characteristics and lifetime degradation of laser diode arrays has been assembled and is described. Performance characteristics for both linear and 2-D arrays can be measured using computer-controlled diagnostics, providing a quantitative and reproducible approach to this problem. The near field is measured by imaging the front facets of the individual emitters onto a silicon detector array with a spatial resolution of 2.5 µm. The far field measurements give the beam divergence over a range of ±45° with respect to the central axis. The spectrum is taken with a gated OMA and can be measured at any time during the pulse with 5-ns resolution. A 150-W pulsed 2-D laser diode array was completely characterized and its output degradation with shot life is reported. Individual data sets were taken on receipt of the device, after 3.5 × 10⁶ shots and after 5.9 × 10⁷ shots. Results show a power reduction of 23% accompanied by a spectral shift to the red of 3 nm.

© 1989 Optical Society of America