Laser apparatus comprising a support that is operative as a heat sink, a diode laser bar assembly, a metallized insulating layer disposed between the substrate and laser bar assembly and an interconnection layer adapted to couple the substrate to the laser bar assembly by means of the metalized insulating layer. The diode laser bar assembly comprises a plurality of laser diode bars having a plurality of lasing sections formed along a lateral edge thereof. First and second metal contacts are disposed on respective adjacent lateral edges of adjacent diode bars, and the metal contacts are separated by a thin layer of metal alloy. One contact forms a positive electrical contact for one laser bar, and the other metal contact forms a negative contact for the adjacent laser bar. A dielectric mirror is disposed on a bottom surface of each of the laser diode bars and an antireflection coating disposed on a top surface of each of the laser diode bars. The present laser apparatus reduces the complexity and cost of diode laser arrays and provides for increased peak power output and improved heat removal. The present diode laser bar assembly may be used in laser surgery systems, solid laser welding, and x-ray photolithography systems where giant pulse solid state lasers are used to create plasmas that generate x-rays. The advantages provided by the diode laser bar assembly are longevity, less heat generation in solid state lasers that are pumped, and greater overall conversion efficiency.