Coherent semiconductor injection laser array

Claim 1

A spatially coherent solid state laser device comprising: a plural element laser array disposed symmetrically with respect to an optical axis; an external resonating cavity formed of spherical lenses and plane mirrors disposed about said plural element laser array with its axis of symmetry coincident with said optical axis; a phase control mode spatial filter disposed in the Fourier plane of said plural element laser array for selecting only the Tem OO mode generated by each of said elements in said plural element laser array, said spatial filter forming a spatially coherent laser beam from the radiation of said laser elements symmetrically disposed about said optical axis so that the waves produced thereby are in phase at an output mirror of said optical cavity, and said spatial filter reproducing the interference function in said Fourier plane which results when the field of each laser in said plural element laser array is in the lowest order traverse mode, and when said fields are in phase said interference function is determined by the number of said lasers in said plural element laser array, their width and their spacing; whereby spatially coherent radiation is generated by each of said elements of said plural element laser array and coupled therebetween to provide a high optical power output in a spatially coherent beam.