Spatial coherence measurement of high power broad area edge emitting laser

We use double reversing wavefront Michelson interferometer to measure the spatial coherence properties of high power broad area Fabry Perot edge emitting blue laser. The measurements are done at different bias current, from lasing threshold up to 1A. The laser is driven in both continuous-wave, CW and pulsed-wave modes. It is found that the magnitude of complex degree of coherence decrease when the laser is driven in pulsed mode. Among driving currents for each mode just for 700 mA bias current more uniform and rather visible interference fringes attained.

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