Linear output coupler for a high power optical ring resonator

An unstable optical resonator comprising:

• a gain medium with pumping means therefor;
• a mirror means for directing optical radiation in forward and reverse traveling modes along a ring path traversing said gain medium, said ring path including an optic axis;
• first mirror means for coupling radiation including a wedge mirror having an opening angle of substantially 90.degree. and forward and reverse faces oriented 45.degree. with respect to said optic axis and disposed on one side of said axis, said forward and reverse faces being oriented to couple radiation in said forward and reverse modes along forward and reverse coupling paths at right angles to said optic axis, whereby coupled radiation in said forward and reverse modes is coupled out of said ring path;
• second mirror means for coupling radiation including an inverted wedge mirror having a first face parallel to said forward face and a second face parallel to said reverse face, said first and second faces being of predetermined size and disposed at predetermined positions along said forward and reverse coupling paths such that predetermined fractions of said coupled radiation are deflected from said coupling paths and reflected back toward said wedge mirror and about said ring path.