Patent ID: 8565272

Claim:
A laser system comprising: a laser gain medium having an active core with a high aspect ratio cross-section, said core including top and bottom wide surface interfaces, and first and second narrow edge interfaces; pumping means for exciting said laser gain medium to generate laser energy; waveguiding means for mode control of said laser energy along a fast-axis direction of said core, said fast-axis direction being perpendicular to said top and bottom wide surface interfaces of said core; resonator means for mode control of said laser energy along a slow-axis direction of said core, said slow-axis direction being perpendicular to said first and second narrow edge interfaces of said core; and a material adjacent to the first and second narrow edge interfaces of said core, said material having a refractive index unequal to a refractive index of said core, said refractive index of said material substantially matching an effective mode index of a particular mode within said core to minimize reflections at said narrow edge interfaces, or said refractive index of said material being higher than said refractive index of said core to make said first and second narrow edge interfaces of said core anti-guiding in said slow axis direction and to increase leakage loss and thereby discriminate against higher order modes in favor of a fundamental mode of the active core.