Gain and index tailored single mode semiconductor laser

A semiconductor laser apparatus, comprising:

• an active layer;
• index guiding means including at least first and second layers disposed about said active layer, said index guiding means for providing optical confinement in the perpendicular and lateral directions for supporting at least one of a plurality of lateral modes and a plurality of perpendicular modes;
• means for providing carriers for radiative recombination in said active layer;
• and
• means for confining the optical gain in a region having a geometry which is substantially matched to an intensity profile of a selected one of said mode plurality, thereby providing a modal gain difference between the selected mode and the remainder of said mode plurality.

A method of providing laser light, comprising the steps of

• providing an active material;
• providing optical feedback to the active material in the longitudinal direction;
• optically confining the laser in the lateral and perpendicular directions such that the laser can support at least one of a plurality of lateral modes and a plurality of perpendicular modes;
• producing optical gain in the active material;
• and
• confining the optical gain to a region that substantially matches, for each plurality of modes supported, a selected mode of the plurality of modes more than at least one other mode of the plurality for providing a modal gain difference between the selected mode and the other mode for favoring excitation of the selected mode.

A method of providing a semiconductor laser having increased output power, comprising the steps of:

• providing a semiconductor layer of active material;
• providing index guiding layers stacked in the perpendicular direction with the active layer therebetween, the index guiding layers having indices of refraction selected for providing optical confinement in the lateral and perpendicular directions for supporting at least one of a plurality of lateral modes and a plurality of perpendicular modes;
• providing optical feedback in the longitudinal direction, including one of cleaving facets of at least one of the layers and providing Bragg reflectors;
• doping at least one layer one of n-type and p-type;
• providing contacts for providing carriers for radiative recombination in the active region;
• providing a gain confining region including a doped region of at least one of the layers, the doped region being doped the other of n-type and p-type, said doped region has a geometry which is substantially matched to an intensity profile of a selected one of said mode plurality, thereby providing a modal gain difference between the selected mode and the remainder of said mode plurality.