We demonstrate the use of a binary diffractive optical element in a very simple setup to convert the multilobed beam from a low fill factor array of coherent laser diodes into a quasi-Gaussian beam. The phase profile of the grating is determined with a phase retrieval algorithm. Experimentally, the conversion efficiency reaches more than 44%. We also establish that this setup can be used to make an effective measurement of the coherency of the laser array.
© 2010 Optical Society of America
Lasers and Laser Optics
Original Manuscript: December 8, 2009
Revised Manuscript: March 23, 2010
Manuscript Accepted: March 30, 2010
Published: May 5, 2010
David Pabœuf, Florian Emaury, Sébastien de Rossi, Raymond Mercier, Gaëlle Lucas-Leclin, and Patrick Georges, "Coherent beam superposition of ten diode lasers with a Dammann grating," Opt. Lett. 35, 1515-1517 (2010)