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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.

Barker binary phase code of maximum length 13 has previously been used for speckle reduction in line-scan laser projectors, and a speckle contrast factor decreased down to 13% has been achieved. In this article, Barker-like binary phase codes of length longer than 13 are used at an intermediate image plane. It is shown by theoretical calculation that much better speckle reduction with speckle contrast factor up to 6% can be achieved by using longer binary phase codes other than the Barker code. Preliminary experimental results are also presented indictaing good speckle reduction.