An engineered current-density profile diode laser (14; 34; 54), comprising: a first portion of semiconductor material (16; 36; 56); a quantum well active region (18; 38; 58) on said first portion of semiconductor material (16; 36; 56); a second portion of said semiconductor material (16'; 36'; 56') on said active region (18; 38; 58); a metal contact (22; 42; 62) on said second portion of said semiconductor material (16'; 36'; 56'); and a plurality of current vias (24; 44; 64) located between said quantum well active region (18; 38; 58) and said metal contact (22; 42; 62); wherein the spacings between said vias (24; 44; 64) are predetermined to provide a desired current density profile (26; 46; 66) per longitudinal direction of said diode laser; said engineered current-density diode laser being characterized in that said current density (26; 46; 66) increasing from a zero value to a first value at a first predetermined position along said longitudinal direction; said current density increasing from said first value to a second value at a second predetermined position, farther in the laser emission direction than said first predetermined position along said longitudinal direction; said current density decreasing from said second value to a third value, lower than the first value, at a third predetermined position, farther in the laser emission direction than said second predetermined position along said longitudinal direction; and said current density increasing from said third value to said first value at a fourth predetermined position, farther in the laser emission direction than said third predetermined position along said longitudinal direction, so that in said engineered current-density profile diode laser local current crowding or longitudinal spatial hole burning effects are reduced. engineered current-density profile diode laser (14; 34; 54), comprising: a first portion of semiconductor material (16; 36; 56); a quantum well active region (18; 38; 58) on said first portion of semiconductor material (16; 36; 56); a second portion of said semiconductor material (16'; 36'; 56') on said active region (18; 38; 58); a metal contact (22; 42; 62) on said second portion of said semiconductor material (16'; 36'; 56'); and a plurality of current vias (24; 44; 64) located between said quantum well active region (18; 38; 58) and said metal contact (22; 42; 62); wherein the spacings between said vias (24; 44; 64) are predetermined to provide a desired current density profile (26; 46; 66) per longitudinal direction of said diode laser; said engineered current-density diode laser being characterized in that said current density (26; 46; 66) increasing from a zero value to a first value at a first predetermined position along said longitudinal direction; said current density increasing from said first value to a second value at a second predetermined position, farther in the laser emission direction than said first predetermined position along said longitudinal direction; said current density decreasing from said second value to a third value, lower than the first value, at a third predetermined position, farther in the laser emission direction than said second predetermined position along said longitudinal direction; and said current density increasing from said third value to said first value at a fourth predetermined position, farther in the laser emission direction than said third predetermined position along said longitudinal direction, so that in said engineered current-density profile diode laser local current crowding or longitudinal spatial hole burning effects are reduced.