Diode laser and laser resonator for a diode laser having improved lateral beam quality

A diode laser, comprising:

• a laser resonator having a gain section, a first planar Bragg reflector and a second planar Bragg reflector, wherein the gain section is arranged between the first planar Bragg reflector and the second planar Bragg reflector and wherein the width of a first portion of the gain section contacting the first planar Bragg reflector is larger than the width of a second portion of the gain section contacting the second planar Bragg reflector, wherein the entire gain section has a gain-guided design, wherein the width of the second planar Bragg reflector is larger than the width of the first planar Bragg reflector and wherein the ratio of the width of the second planar Bragg reflector to the width of the first planar Bragg reflector is between 1.5 and 20 and wherein the width of the first planar Bragg reflector is smaller than the width of the first portion;
• and
• electrical contacts for injecting electrical charge carriers into the gain section.