Design and fabrication of diffractive optical element applied to vertical-cavity surface emitting laser.doc

In this paper, a new application strategy of diffractive optical elements (DOEs) has been proposed. The research combined vertical-cavity surface emitting laser (VCSEL) with diffractive optical elements into a single opto-electric semiconductor device. In order to fabricate DOE-VCSEL, DOE surface profile can be integrated upon P-DBR layer of VCSEL structure by using semiconductor processing. We used scalar diffractive theory, Dammann grating and Fresnel lens concept to design DOE surface profile. From simulation, we determined the element size of 488 × 488 μm2. Experimental result shows the divergence angle of 8 degrees of DOE-VCSEL can be reduced. So, the design and fabrication of diffractive optical elements structure on VCSEL can achieve the effect of output beam concentration. Compared with a conventional fiber coupling system that uses a plano-convex lens, our design has the advantages of simplicity for fiber coupling systems.