Patent ID: 8913645

Claim:
A laser cavity, which makes it possible to produce at least one laser ray ( 6 ) and which comprises: at least two mirrors ( 2 A, 2 B); a plurality of active elements ( 3 ) having propagation axes ( 5 ), said active elements ( 3 ) being arranged between these two mirrors ( 2 A, 2 B) and being able to undergo pumping so as to amplify the laser beams ( 4 ); an extraction unit ( 7 ), which is arranged in said laser cavity ( 1 ), which comprises at least one polariser ( 8 ) which is at an inclination to said propagation axes ( 5 ), and which is formed, so as to carry out a central extraction of the laser beams ( 4 ) to obtain the laser ray, said extraction unit ( 7 ) being arranged in said laser cavity ( 1 ) so as to divide it longitudinally into two functional parts (P 1 , P 2 ), of which a first part (P 1 ) comprising said active elements amplifies said laser beams ( 4 ), wherein said extraction unit ( 7 ), which comprises at least one retardation element ( 9 ) which is arranged longitudinally upstream from said polariser ( 8 ), divides the laser cavity ( 1 ) longitudinally so as to form a second part (P 2 ); and a common region in said second part which coherently couples said laser beams ( 4 ) by superposition to form a combined laser beam that follows a single path ( 13 ) and is reflected by the second mirror ( 2 B).