Patent ID: 7242702

Claim:
A laser apparatus for producing single mode large-area coherent lasing, comprising: a feedback structure of a thickness T and of an average refractive index N, having a top surface and a bottom surface, said feedback structure having a refractive index variation between said top and said bottom surfaces in accordance with a predefined profile, such that said structure produces a photonic mode having a lasing threshold and being of a predetermined frequency, and a plurality of additional photonic modes, wherein said predefined profile is selected such that said predetermined frequency is greater than a value determined by a following expression: F L +c/ 2 TN, wherein F L is a frequency of a nearest, to said predetermined frequency, lower frequency photonic mode of said plural additional photonic modes, and c is the speed of light in a vacuum; a light-emitting medium disposed within said feedback structure, said light-emitting medium being configured to emit electromagnetic radiation at said predetermined frequency; and variable excitation means, connected to said feedback structure, for exciting said light-emitting medium to produce optical gain of a predetermined gain magnitude in said feedback structure, said predetermined gain magnitude being sufficient to at least meet said lasing threshold to cause coherent wide-area laser emission to occur at said predetermined frequency perpendicular to at least one of said top and bottom surfaces, wherein said wide-area laser emission remains coherent when said predetermined gain magnitude is selectively increased above said lasing threshold.